Congrats on this submission! Crunching a project on a game engine that is new to you is no easy feat. The graphics were cute and reminded me of old HTML5 games I used to play.
As far as feedback, an easy addition that would be nice is adding some basic SFX for things like taking damage, firing, killing enemies, etc. Stuff like this really helps communicate to the player what's going on in addition to the visuals! They don't have to be major, you can just record yourself going 'pew-pew' or 'ouch' and that would work :)