-Make rideable vehicles! Like Bolly with Robot Boss legs, that one that I created in my hoax ;P
-Stealth levels. I think that can be made with DoggyDogs and mad hatters.
-New playable chars? Hmmm...
-Make foggy levels...
-...Or even 3D levels!
-Make me appear in Credits list! (LOL, J/K )
-New enemies. Use tiles and Hurt events.
-Turrets!
-Make it all, and it will be really good!

Thats all by now!