Enough Pieces to Build a Game?

I believe I have enough functionality in my 6502 system now to take a run at developing a retro-style game. So far, I have built support for:

• PS/2 keyboard input

• USB mouse input

• Joystick input

• Audio output

• VGA output

I've never developed a game (much less on a 6502), so this will be interesting. I've just started experimenting with sprites.

So much to learn...