Really enjoyed this.
One issue I had was for when low to the ground I kept moving my mouse off the playscreen and clicking off. best way to combat this for players is just fullscreening the browser and have the playscreen touch the bottom. I think it would be nice to have an option to fullscreen the game to eliminate this problem.
Also had a once off issue with hitting the side near the top of a crate and sort of clipped to the top of it which didn't break the crate. tried to recreate it but not luck.