Nice game
Reall well done game. I love the way you gave instructions at the start, and I do like the simplistic styling as well.
A few things I noticed though:
Walls can be damaged from either side but damage only appears on the left.
Enemies deaths don't really show well. You need to make it clearer that an enemy is dead and not just wounded.
More instructions! I think it would be cool for example when you get to the falling blocks bit for there to be instructions written on them.