Oh, good thread.

- Can spin-jump on enemies
- Silver P-Block, like in SMW
- Can carry switches and P-Blocks
- Can look up, throw items upward
- Green, red, yellow, and blue Koopas and Yoshis (and their SMW abilities fire, stomp, fly)
- Shell-less Koopa
- Shell-less Koopa (can kick shell)
- Invincible shell
- Baby Yoshi (can hatch if fed)
- Stationary Power-Ups
- Secondary Item Box
- Thwimps, Giant Thwomps
- Option to disable collision in multiplayer
- Option to disallow multiplayer "bubbling" (dead is dead)
- Cape (impossible...)