Somehow I had not logged this one in, weird! Let me paste my steam review here (I don't think I ever reached the final boss, but the review should clarify why; still gonna chip away at it and see what I can do about it):

Progression can feel maddeningly slow due to the veeery little incremental upgrades you get, I wish it was just a bit more generous with them. Also the walking animation with the standard guns drives me CRAZY, for a game all about being acrobatic and jumping around you would think one of the animations you will see the most would be better (I know, absurd nitpick, it's just been eating me inside for years). Anyway, pretty entertaining, looks nice, hope they make something else building on top of the premise.