It's fine. All this can be easily shown in the demo I can put together. The falling stuff, though, will take a bit of coding, but I'll explain it in the code window (when leaving comments in GML coding, comments are preceded by a // and the words are italicized, so the comments will look something like this:
//this code checks to see if blahblahblah)
I have...what...five hours left til I leave work. It'll take me a bit to make the demo but I should have it ready by 10 at most if I'm not delayed by dishes waiting to be washed...(dirty dishes are pure evil cuz I get stuck with them all the time...)
After a while Game Maker gets pretty easy...you just gotta find out what the functions do in different cases. Took me a while, though, and I'm still learning. My current game is chock full of coding and it's all the simple stuff...you'll soon get the hang of it, though.
EDIT: I'm terribly sorry to say this but GM's giving me issues...I hate this computer. Also I thought it'd be easy to do with D&D but in order to get around some spritechange difficulties there's coding. I'm explaining it though...
Man I hate this...if it gets here late, I'm very sorry...didn't expect my computer to not be able to handle various programs tonight of all nights...
I've made some progress though, so don't worry. Biggest issue here is that the jumping sprite won't change into the falling sprite unless a key is held, I'm working on fixing that. Or would you want to use just one sprite for both jumping/falling? That clears a lot of trouble there.