Hey jamzilla thanks for your interest in the jam!
Your game should be playable with a maximum of 12 controls (0 - 9, *, and # key on the Nokia 3310). For reference Space Impact and Snake used 6 keys to control the game. The control scheme is up to you but I would suggest your game be playable only using a keyboard.
Detailed examples:
Space Impact Controls
8 key: move up
0 key: move down
# key: move forward
* key: move backward
1 or 3 key: fire laser beams
4 or 6 key: fire special weapon
Snake (II) Controls
2 key: snake goes up
4 key: snake goes left
6 key: snake goes right
8 key: snake goes down
* key: snake turns left
# key: snake turns right
Ill be sure to add this to the page. If you need more clarification let me know!