Is imitation the sincerest form of flattery?
Lets not fool ourselves what we are dealing with is a Super Mario Brothers clone. You added some gory stuff and an interesting if too complicated.
Too complicated? You might hear yourself saying. Why yes. What made Super Mario Bros. So inviting was that it had only one kind of jump. Yes, they added ground pounding and stuff later, but it wasn't really required until the 64 days.
So you've cluttered up your game. That's not where it falls short. It really falls short in the technical department. Your collision detection for jumping on enemies is God awful. I often tried to stun the enemies with a jump only to land on their elbows and die. Now yes you have unlimited lives, but it just seems like a cheap fix to the poor detection.
That's where it falls down. I often spend so much time redoing parts I've done several times only to die by some jump that was a few pixels off. The pace is also slow with no running, and the blatant rip-offery make me score this in the middle. It had good graphics and sound though.