OK, let's test out that this worked. Restart the Arduino IDE and select the board you'll be uploading to, then open the Arcada Arduboy2 examples. Start with HelloWorld

Once you've got that working, and Hello World appears on the screen, move onto Buttons demo, try moving the text around with the D-Pad/joystick and A+B buttons

Finally - load up the Breakout demo to play a real game!