I sent a pm praising how awesome I felt this hack was, and stating I wanted to take a go at redesigning the character sprite. So, here's my go at it:
I wasn't quite sure based on the low res youtube videos, but from the few screenshots it looks like you've got two 16x16 sprites for his upper half, one looking straight and one looking up, and 5 16x16 lower half sprites, 3 for walking (with an A,B,C,B.. pattern), one for jumping, one for flying, and a 16x8 lower sprite for crouching. As for the jetpack and the crouching, maybe I'm wrong, but I gave it a shot.
In the top left is actual pixel size. Then we have each unique sprite. And the bottom shows the combinations of each lower frame with each upper frame.
Anyways man, use it if you like.
If not, chalk it up to some of your first fan art.