So i saw this cool contest,and I'm currently available,
I program in AS2 thought,hope that isn't a bother ....

so far I've done a turn base rpg engine,a platformer and a mouse avoider with some added elements that I don't think i'll ever finish :D

I thought a example would do nicely :)

arrow keys to move ,
a to jump/fly
hold down+left/right to charge up (takes aprox 2s) then you move fast awhile,

the enemy doesn't attack ,this is not the full engine...i have static enemies,moving ones that can be killed when squished(jumped on),collectible coins with an air combo system , and hit invulnerability

http://spamtheweb.com/ul/upload/150509 /77327_prog_jump.php

EDIT:
posted the game with more features,the rat has kinda poor hit detection didn't really work on it :) it can be better,
if you combo 5 coins the air you get one more,if 10 you get 2 more and so on....also the blue things don't damage :)
http://spamtheweb.com/ul/upload/150509 /77819_redux_blorg_j_then_flight.php