Overview

Side-scrolling platformer games are some of the most popular games ever made. Where would we be without Super Mario Bros. for Nintendo Entertainment System? It's too chilling of a question to even consider!

But, here's a question we will contemplate -- how are side-scrolling platformer game levels made? In this guide, we'll learn how to make our own levels using tile maps and sprites all inside of MakeCode Arcade. You'll then be able to play your own levels in the browser or even on a handheld device, such as the Adafruit Pybadge or Pybadge LC.

Parts

You can create and then play the game entirely in the web browser (we recommend Chrome) or, you can upload it to the Pybadge for an authentic handheld gaming experience!

Adafruit PyGamer Starter Kit

PRODUCT ID: 4277
Please note: you may get a royal blue or purple case with your starter kit (they're both lovely colors)What fits in your pocket, is fully Open...
OUT OF STOCK

Adafruit PyBadge for MakeCode Arcade, CircuitPython or Arduino

PRODUCT ID: 4200
Coming soon! Sign up to be notified when we have these in stockWhat's the size of a credit card and can run CircuitPython, MakeCode Arcade or Arduino? That's...
OUT OF STOCK

Adafruit PyBadge LC - MakeCode Arcade, CircuitPython or Arduino

PRODUCT ID: 3939
What's the size of a credit card and can run CircuitPython, MakeCode Arcade or Arduino even when you're on a budget? That's right, it's the Adafruit...
OUT OF STOCK

Pink and Purple Braided USB A to Micro B Cable - 2 meter long

PRODUCT ID: 4148
This cable is super-fashionable with a woven pink and purple Blinka-like pattern!First let's talk about the cover and over-molding. We got these in custom colors,...
$3.95
IN STOCK

Lithium Ion Polymer Battery - 3.7v 350mAh

PRODUCT ID: 2750
Lithium ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light and powerful. The output ranges from 4.2V when completely charged to 3.7V. This battery...
$6.95
IN STOCK

Adafruit Circuit Playground Lanyard

PRODUCT ID: 3987
We've got our Circuit Playground friends on lunchboxes, 
$1.95
IN STOCK

Platformer Level Fundamentals

Screen View vs. Level Map

One of the quintessential design elements of most platformer games is the side-scrolling movement of your character through the game level (also called the map). This means the player is presented with a camera view on screen that is smaller than the overall level.

By contrast, a game like Space Invaders or Pac-Man is played on a screen that represents the entire level. The player's character and the camera never leave the one playing field (although flying saucers do enter and exit horizontally at the top of the screen in the case of Space Invaders. Where are they going?)

gaming_file-20180531-69508-1oenzpj.png
Space Invaders (BagoGames, CC BY)

However, in a game such as Super Mario Bros. or Sonic the Hedgehog, the level is much, much larger than what fits in the screen's view at one time. So, by scrolling the character and camera as the player moves through the level, the map is revealed.

Here's the player's camera view seen on screen during gameplay:

gaming_mario_screen.png
Super Mario Bros. screen

This, on the other hand, is a view of the entire map of the same level:

gaming_mario_full_map.png
Super Mario Bros. full level view

Map/Level Making

In order to create a map for the level, you need to let the game engine know where the ground, platforms, obstacles, and goals are. In most 2D game engines, the level starts out as a blank grid, sort of like graph paper, and it's the level designer's job to build the map of the level's gameplay on that grid.

In the early days, this would, in fact, be created first on graph paper by the level designer, and then translated into game level code by the programmer. Here's an example from 1985's Super Mario Bros. of a level designed by Shigeru Miyamoto and Takashi Tezuka:

(This example drawing was taken from this behind-the-scenes video by Nintendo.)

Here's what the level looks like in the game engine, although this is a zoomed out view, not the player's screen:

Tile Mapping and Tile Sprites

Not only does the level design indicate where the ground, walls, platforms, obstacles, and goals are located, but we can also indicate the artwork of the level, which defines it's look. Rather than lay one huge piece of pixel art across the whole screen, the same grid system is used to display individual tiles of sprite artwork.

You'll notice there is a lot of repetition in the visual design. This is because a limited number of small sprite images are being replicated across the whole level. In fact, if you look at the example above from Super Mario Bros., there are only four sprites used to define the level (excluding power-ups and enemies).

This tiling is done to save memory. Here's an excellent guide page by Ladyada on some of the details of tile mapping and memory usage related to the NES and the Fuzebox, but the principles apply to MakeCode Arcade and the Pybadge/Pygamer as well. Here's an excerpt:

Graphic displays such as televisions, computer monitors and LCDs all display graphics made up of pixels (picture-elements). Early VGA monitors displayed 640x480 pixels. Nowadays, hi-definition (HD) displays these days can be 1920×1080 or even higher! The Fuzebox isn't powerful enough to drive HD but it can do pretty well for normal TV, at 240x224 pixels. Even though that doesn't sound like much, most original 8-bit video game consoles had the same resolution & the games were pretty cool.

Since the display changes during the course of the game, that would imply that we should store the video data in RAM. If each pixel contained 8-bits (one byte) of data, that would mean we need:

240 pixels wide * 224 pixels high * 1 byte per pixel = 53760 bytes = 52 Kilobytes

to store the video map in memory. Even though that doesn't sound like a lot, it is for a small microcontroller: the total RAM available is only 4K! Since there's no way to cram the video data into RAM we perform a trick called tiling. basically, we say "OK our simple games will have a background or images that don't change much, or repeat. So instead of having each pixel be unique, we'll use a range of predefined tiles". For example, lets look at this screenshot of Super Mario Brothers, the best known 8-bit game

Notice how the bricks at the bottom are just copies of one 'tile'? Also the clouds are cloned-looking and the bricks also look identical. Even tho this image has a resolution of 240x224, there's really only a grid of 15x14 tiles, each one 16x16 pixels big (verify this by counting how many bricks run along the bottom of the screen).

The Fuzebox uses much smaller tiles, because it actually has more processing power than the original NES. It uses 6x8 pixel tiles, for a grid of 40x28 tiles. Assuming that we reuse most of the tiles (and, in general, you'll see that many are) we can cut down the amount of memory needed to store the video graphics. In addition, because the tiles don't change (they just get swapped around), we can store them in the flash memory (which is 64K large) instead of the RAM. Basically, our video memory problems are solved!

Lets say we have 6x8 px tiles and a range of maybe 512 tiles maximum. that means we need

6 *8 * 512 = 24 KB

of flash storage to keep all the tile (which is totally reasonable since we have 64K of flash available), and then in the video RAM we will need:

40 * 28 * 2 byte address = 2240 = 2KB

of RAM memory to store the current map, about half of the 4K we have available. Now we can actually do that!

 

Level Design Example

Tile Map

Here's an example of tile mapping and level design in action. First we design the level, indicating where the ground, obstacles, platforms, and goals are. Each color index indicates a different type of object. These can also have different conditions applied to them when the player sprite makes contact, such as points earned when the yellow tiles are touched, or loss of health when the red tiles are touched. You can think of this as the equivalent of the graph paper version of the level.

Tile Sprites

Pixel art sprites have been created for each different surface or object type used in the level.

We can see the correlation between the indexed color tiles and their associated sprite artwork. Wherever a tile map of a particular color index is placed on screen, the associated sprite artwork will appear.

Here we see the level tile map with the sprite artwork applied.

In most cases here a 16x16 pixel sprite has been used -- the two exceptions are the pipe and flagpole which are both larger sprites.

Camera

You can think of the player's view of the game screen as the view through the player "camera". We have a level map that is larger that what we can view through this camera, and as the player moves, the camera moves with them, revealing new, unseen parts of the level.

Typically, the player sprite can move around a bit in the camera view, but most of the time, the camera stays centered on the player, as if it is tracking along on a camera dolly.

The image here is used to illustrate this idea, but note that in a simple 2D game there isn't really a 3D model of the game level inside the code!

Motion Parallax/Multi Plane

A great way to give the illusion of depth in 2D games is through motion parallax, which is the phenomenon of distant objects appearing to move more slowly than nearer objects do, relative to a the changing viewpoint of a person or camera.

You can see this in effect by simply holding up one finger in front of your face and then moving your head from side to side. The finger will appear to move a lot while objects you can see in the background will move relatively little.

This phenomenon was used to great effect in early 2D animation by Walt Disney animation studios with the invention of the multi-plane camera system. Here's a great video explainer by Disney himself (note that the example is of a camera push, but the same applies for a horizontal dolly or crab shot):

Different game engines will handle motion parallax in various ways. There may be multiple depth planes, similar to the Disney example, or just two set planes for the background and the level. In this example from MakeCode Arcade, we can think of the level tile map as being fixed in place, while the camera, character sprite, and background dolly through the scene.

Note, this is only used to illustrate the concept, there is not a 3D model in the MakeCode Arcade game engine!

Now that we have the fundamentals down, let's create a side-scrolling platformer level tile map in MakeCode Arcade!

Create a Tile Mapped Level in MakeCode Arcade

MakeCode Arcade

If you're not already familiar with the basics of MakeCode Arcade, check out this guide on creating a character sprite and moving it with controls. First, open a new Chrome browser window (Chrome works best) and go to MakeCode Arcade beta.

You can also take a look here to learn how to set up animation for your character.

Game Prep

We'll start off with a pre-made scene in which the basics of the character sprite, animation, and movement have been created, just so we can focus on level design.

Open this link in the Chrome browser to get going: MCA_ruby_level_0

Game Prep

We'll start off with a pre-made scene in which the basics of the character sprite, animation, and movement have been created, just so we can focus on level design.

 

Open this link in the Chrome browser to get going: MCA_ruby_level_0

 

Click the Show Code button.

 

Then, click the Edit button to open the code into the editor.

Add Background

We'll add a background image first. Click the Scene category, and then add the set backround image block to the on start block.

 

Click on the empty sprite block to open the sprite editor and then paint and draw your background image. Note that this is a 160x120 pixel sprite, which is the full screen size of the MakeCode Arcade game screen.

 

It can be tricky to paint accurately on the small canvas, but after some trial and error I came up with a background I liked.

You can get an exact copy of the code up to this point by downloading this .png file, which has the game code embedded in it! Right click the image and pick "Save image as" to save it to your computer's hard drive, then drag the saved image right onto your MakeCode Arcade page in your Chrome browser window!

Create Tile Map

Now we'll create the tile map, which is the foundation of our level.

 

From the Scene category, drag a set tile map block from the Tiles sub-heading into the on start block.

 

We'll open the sprite editor for the tile map in order to draw out the level. The first thing we'll notice is that the default canvas is the wrong size and shape for a side scrolling platformer. Currently, it reads 10x8. Click on that resolution button multiple times to get to the size we want, which is 32x8.

 

Let's create a ground running across the bottom of the level. Use the blue color index and a single pixel pencil tool to draw the two ground layers. You can hold the shift key on the keyboard to constrain the tool to straight lines, which is very helpful! If you make any errors, just use the eraser tool to correct them.

 

It's important to note that the tile map resolution is different than the screen resolution. We're using a 32x8 pixel map where each pixel represents a 16x16 pixel tile in the final game. The screen resolution is 160x120.

You can see that the tile map actually shows up in the game engine now at proper screen resolution. Before we add the tiled sprite artwork, let's add some platforms to the tile map.

Add Platforms

 

Click on the tile map to open it again into the sprite editor. Place purple tiles onto the map as shown, then click the Done button.

 

Now we can see in the simulator the purple platforms in the visible portion of the tile map.

 

Try moving the Ruby player sprite using the arrow keys to explore more of the level.

 

Uh oh, we can't! Ruby walks right off the edge of the screen!

 

This is because we haven't yet told the in-game camera to follow Ruby.

Camera Follow Sprite

From the Scene category, add a camera follow sprite block to the on start block.

 

Pick Ruby from the variable dropdown menu.

Now, when Ruby reaches the center of the screen, the camera tracks along with her and we can walk over to the previously unseen portions of the tile map.

Tile Sprite Art

Now, we'll really start to put the tile map to use by adding sprites. For all of the purple tiles, we'll add a sprite of pink blocks, and for the blue tiles, we'll add a sprite of ground blocks.

Add a set tile <index color> to <sprite> with wall block from the Scene category to the on start block.

 

Choose purple for the index color by clicking on the color swatch and selecting the purple swatch. This means that whatever sprite art we create and wall state will apply to all purple tiles in the tile map.

 

To create the block art, click on the sprite swatch and then use the pencil tool in the editor. You can get creative here, the block can look like anything you want inside of 16x16 pixels! (You can actually use other sizes, but for now we'll stick with this standard for most blocks for the best fit.)

 

Lastly, we want to indicate that our player sprite will not be able to overlap the purple tiles, but instead bump into them or jump onto them. Do so by flipping the with wall switch to on.

Ground Blocks

Let's give the ground tiles a sprite as well. You can duplicate the previous set tile block, then change the index color to the same blue you used for the ground tiles.

 

Create some artwork for these ground blocks in the sprite editor, and then click Done.

Now that we've got a ground tile in place, we can add "gravity" to the scene. This will help return Ruby to earth after she jumps. We'll do so by setting Ruby's acceleration on the y axis to 300, instead of the zero it was previously set to when the scene was prepared.

Add Gravity

Find the Function prepPlayer block in the scene.

 

In the set Ruby ay (acceleration y) block, change the value to 300.

Now, you can try jumping with the A button and you'll see Ruby jump up, then land on the ground, since it has the "wall" flag turned on.

Add Tiles

Now we can fill out the level a bit more by adding more platform blocks, a question mark block, a lava pit, a pipe, and a flagpole at the end of the level. For each distinctive type of block remember to use a unique color so you can add a tile sprite to it later.

Note, we'll used four tiles for the pipe, since we want the artwork for it to be larger than a single tile.

You'll notice that I've used two different color indices for the ground now -- there are standard ground blocks on the bottom layer and a variant that has a mossy top on the top layer.

Here's the full set of tile sprites and their indexed colors for the tile map:

Tile Sprite Sizing

Note how the single green tile is placed one tile unit above the ground and has clearance on it's right side -- this is because I created a larger, 32x32 pixel sprite for the pipe tile.

 

This means that the artwork occupies the space of four tiles and is a great way to create elements of different sizes, which can give your game level more visual interest than having every tile the same size.

This is what the full set of tile maps looks like inside of the on start block.

Tile Collisions

Another use of the tile map is to indicate when special events occur based on player sprite collisions with certain tiles. Again, the tile index color is used for this

For example, we can have a tile collision cause the player to earn points, and play an effect animation, or remove player lives, and even set the win condition for the game.

Collision Effects

 

From the Scene category, add an on sprite of kind Player hits wall block to your canvas.

 

We'll set this one up to add points when the question mark tile is hit. Going back to our tile map we can see that the question mark tile index color is yellow, so we'll change the index color of this collision block to yellow as well.

 

Next, we'll add an effect block. From the Sprites category, add a mySprite start spray effect block to the collision block as shown.

 

Change the drop down menu to Ruby for the sprite and the effect to fountain.

 

Lastly, click the + plus sign to have the effect only last for 500ms.

Add Points

Not only will we play an effect animation when Ruby hits the question mark tile, but we'll also add points!

From the Info category, add a change score by 1 block to the collision block as shown.

Game Over

The last thing we'll do is set up the red tile (lava) collision to cause a game over of type "lose" and a light blue tile (flag pole) collision to cause a game over of type "win".

Create or duplicate two more on sprite of kind player hits wall collision blocks. Set one to red tiles and the other to light blue.

From the Game category add a game over block to each of the two new collision blocks.

Set the red collision game over to type "lose" and the light blue on to type "win" by flipping the toggle as needed. (Depending on the version of MakeCode Arcade you're using you may need to first click a + plus sign to see the toggle switch in the game over blocks.)

You can now play your level! Try jumping up to the question mark for points, fall in the lava to end the game on a loss, or make it to the finish line!

You can download the .png with the code embedded here if you want to see the final version:

You can get an exact copy of the final game code by downloading this .png file, which has the game code embedded in it! Right click the image and pick "Save image as" to save it to your computer's hard drive, then drag the saved image right onto your MakeCode Arcade page in your Chrome browser window!

Next, we'll upload the game onto to the Pybadge!

Update the PyBadge/PyGamer Bootloader

You are at the bleeding edge of handheld, open source, game playing hardware and software, what with your PyBadge/PyBadge LC or PyGamer! Congratulations! It's fun and exciting! It is also changing and improving all the time, so please update your bootloaders before proceeding to put your MakeCode Arcade games on the board!!

Among lots of other reasons, update the bootloader to prevent a problem with MacOS 10.14.4, to fix button problems, and get the thumbstick to work!

PyBadge/PyBadge LC Bootloader

If you have a PyBadge or PyBadge LC, please go to this page for instructions on updating the bootloader.

A HUUUUUUGE number of people have problems because they pick a 'charge only' USB cable rather than a "Data/Sync" cable. Make 100% sure you have a good quality syncing cable. Srsly, I can't even express how many times people have nearly given up due to a flakey USB cable! Enter Alert Text...

Hardware Checks

If, after updating your board's bootloader, you still think you may have a hardware problem, here's a great way to test out all of the functions. From buttons, to the light sensor, thumbstick (PyGamer only), accelerometer (PyGamer and PyBadge only, not the LC), and more, we've got a super nifty set of hardware test .UF2 files you can use.

Click on the link for your board below for more info and a link to the appropriate UF2 file.

Another way to do a hardware check is with the handy, dandy MakeCode Arcade Basic Hardware Test. This was created with MakeCode Arcade and you can use it to check that your d-pad buttons or thumb joystick can move the yellow face around the screen, and that the A and B buttons work to play a sound (just make sure you have a speaker plugged in to the PyGamer first).

You can open this link to get to it, or download the UF2 file below and drag it onto your board's USB drive in bootloader mode.

Load a MakeCode Game on PyGamer/PyBadge

Let's load a game! For example, here's a link to Run, Blinka, Run! To open the game in the MakeCode Arcade editor, first, click the share link below. This will allow you to play the game in the browser right away.

Then, click on the Show Code button in the upper left corner. The shows the code for the game, and by clicking the Edit button in the upper right corner, it'll open into the editor where you can upload it to your PyGamer/PyBadge.

Once you have a game working on the MakeCode Arcade web editor, it's time to download it and flash it onto your board.

Please only use the Google Chrome browser with MakeCode! It has WebUSB support and seems to work best

Board Definition

In order to load a game made in MakeCode Arcade onto the PyBadge, first choose the proper board definition inside of MakeCode. Click the gear icon and then the Change Board item.

Change Board screen


Click on the image of your board, either the PyBadge/PyBadge LC or the PyGamer

This will cause the game .uf2 file for your particular board to be saved to your hard drive. You only need to do this the first time you use a new board. Thereafter you can simply click the Download button on the MakeCode Arcade editor page.

A HUUUUUUGE number of people have problems because they pick a 'charge only' USB cable rather than a "Data/Sync" cable. Make 100% sure you have a good quality syncing cable. Srsly, I can't even express how many times people have nearly given up due to a flakey USB cable!

Bootloader Mode

Now, we'll put the board into bootloader mode so we can drag on the saved .uf2 file. On the back side of the board you'll see a reset button at the top. Make sure the board is plugged into your computer via USB with a USB micro B to A data cable. Also, be sure the board is turned on.

 

Then, press the reset button. This will initiate bootloader mode.

 

When the board is in bootloader mode you'll see a screen similar to this one show up.

Drag and Drop

Now that the board is in bootloader mode, you should see a BADGEBOOT drive show up on your computer as a USB flash drive. Simply drag the arcade game .uf2 file onto the drive.

Play!

That's all there is to it! Once the file is copied over the board will restart and launch the game!

Keep an eye on Adafruit.com for additional game related content.

Troubleshooting MakeCode Arcade

If you run into trouble with MakeCode Arcade, here are some resources for getting help:

Only use the Google Chrome browser with MakeCode!
This guide was first published on May 10, 2019. It was last updated on May 10, 2019.