Yo, it's a NES game!

Sort of. It will get better.

Milestone list:

1- (DONE) Boot a ROM that does nothing 
2- (DONE) Single sprite visible on the screen
3- (DONE) Complete complex (multi-part) sprite visible on the screen
3.5 - (DONE) single background tile visible on the screen
4- Swap palette of sprite in response to gamepad
5- Move sprite on screen with no animation
6- Display a full tile map on the screen
7- Collide a sprite with the world map
8- Apply gravity to a sprite and have him stand on the "ground"
9- Jumping sprite in response to the gamepad
10- Scrolling tile map (moving camera)
11- (DONE) Add a second actor/sprite to the screen
11.5 Make all visible actors stand
12- Collide two actors with each other
13- Create actors on screen from map data (e.g. some data in RAM)
14- Change an actor's sprite based on its state
15- AI update functions for each actor type called once per frame
16- Play a sound effect based on a collision event
17- Loop background music
18- Tilemap transitions (e.g., end of level)