(Space)-Shoot from cannon (Up arrow)-Jump or speak to NPCs (Down arrow)-Crouch (Left/Right Arrows)-Move (M)-Change the music (N)-Mute the music (T)-Chat (Buzzer goes off if message contained words not in the dictionary) (C)-See chat There are character abilities!
Credit to Nintendo, Intelligent Systems, makers of SMBX, music rippers, and sprite rippers.