Really cool game, loved the song and the art! (and the fast paced? gameplay)
Found some cheese opportunities due to level design or bugs:
-Some times spikes wouldn't cause damage and would let me stand on them;
-You can faze through walls using the grappler;
-You can skip some portions of some levels by ignoring walls with spikes and wallclimbing elsewhere;
Upon starting the game I was kinda confused by how fast the character was moving, and I was wondering if such speed was due to framerate being high. The difficulty I faced when trying to complete the last level, which (I think) requires precision jumps, kinda supported that idea.
If the game is actually as fast as I experienced it, another little suggestion I can make is to reduce the time it takes to transition through levels, since it breaks the fast pace the game builds on.
Besides all the criticism (that i hope will help you!) I really enjoyed the game!
Managed to shave a score of 500+ to 185!