Thanks a lot for playing and giving feedback. I liked the wall bounce effect as well, and did consider the possibility of allowing for a player to chain it up to 3 times, but I chose to stick to just the one. And man, that boss effect made me laugh so hard when I first beat it after implementing that effect. You're dead on about the anime-ish quality to it. Like a samurai slicing through the enemy, a moment where nothing happens, and then the blood sput happens. One of the highlight of making the game was that little detail.
As for the criticisms, the little lift you get on release was bug that I ended up just accepting. It was introduced when I implemented variable jumping. And yeah, too many simultaneous explosions caused lag most likely due to the the amount of physics objects interacting with each other.
Thanks again for the feedback!