Awesome job -- I played through the whole game. The difficulty seemed just right.
It wasn't immediately clear that you could reflect the archers arrows, which caused me quite a bit of trouble on some levels.
I feel like there's too many enemies where you just spam attack to continue knocking them back. The red squares/big red squares, ghosts, those fast squares, the frog things, etc. Could maybe use some enemies that can't be knocked back and you have to dodge their attacks. I really liked the archer reflect mechanic because it was a different way of killing them and felt really satisfying. I even managed to get two archers to kill each other.
I was wondering if anyone was going to attempt to do 100 levels, but you did it, and pretty well at that.