What a nostalgia trip!
This game really brought me back to my old miniclip days in junior high and high school! Simple level design, character design, objective, etc., but smooth and effective controls, along with fun sound effects and animation makes this a nice little 2D level-based shooter!
The only suggestion I would have would be to potentially add some form of weapon or ability that could mess with the level design in some way! I think that could be pretty interesting, if implemented in the right way! More of an idea than a suggestion, but still! Enjoyed the game overall, and very thankful for the opportunity to play it! :)