All right, so I poked the Spelunky source code in Game Maker Lite, and it seems like there's a lot I
can do, but there's even more stuff that I
can't. So unless I shell out $25 for the full version, looks like I will need help making this after all. I can still do sprites and stuff, though.
MGG, once I finish making the playable ManTrap sprites, I'll cash in that free game-making favor and have you place those sprites in the mod. Beyond that, well...banna8? Anybody? A little help?
Oh, and I might as well tease you a little. I plan on adding two more kinds of Mantrap to the mod:

The yellow one is a Venus Mantrap, and they'll live in the temple. The blue one is a Tunnel Mantrap, and they'll live in the ice caves. You'll also play as both of them by going in either of the Changing Rooms.