Okay, I'll bite:
Rocket Frogs: is it possible to make an enemy that fires a system when it smacks a wall? That's not something I've tried before and the XML documentation is a labyrinth of many floors with traps and, I dunno, clowns everywhere, so I'm not going near that right now. But if so, what about an enemy that makes a violent charge at the player (like those dog things do), except with alot less ability to turn, and if it smacks a wall, a bunch of "shrapnel" shoots backwards at random angles? The idea partially comes from the original Metroid: those things that would fall from the ceiling and "drill" into the floor, and in the process they'd spray a wave of projeciles outwards. And I figure, a frog with a rocket wouldnt be a very coordinated frog, so... smacks into walls!
Crazy as a spider on rollerskates: .....Rocket frogs with additional caffiene?
Movable blocks: Yes, I'd love this one. Something tells me it'd be some sort of giant hassle for them to make though. But it could be pretty great.
Bullet-time: Ooh, that'd be neat. What about a consumable that does this? Considering the sort of thing the Redshift can do, I'd guess that the game is capable of this. Maybe.
Koopa: Well, Super Mario Bros, the first game, he breathes fire from like a million miles away, the flames go through everything, we've got an enemy that does the same thing, so.... boss version of a Blaze Cannon? ....this is SO tempting but it sounds like a mad science experiment that could go horribly wrong. Needless to say that just makes it more tempting. It'd also drive players crazy, of course. Even MORE tempting.
Power Rangers: What.