Great game, awful control...
Whenever I am in the mood for an old-school ass whooping, I can always count on Megaman, Battletoads, Blaster Master, or IWBTG. Yes, I've played IWBTG... and yes, I know how bloody hard it is. On it's own merits, this game is a faithful fanmade "spiritual sequel".
But at least with games aforementioned, whenever I die... I know it's my fault and not the game. The object collisions, weird physics, and the controls in general are awful. Intentional or not, it severely dampens any given game. At least half of my deaths alone were from the iffy double jump reaction.
The choice of music is decent enough. The visuals aren't really anything special, but I can definitely go without that seizure inducing area before the Donkey Kong area ( my eyes still hurt from that ).
You have a great game underneath here, but please fix the controls and collision detection.