This needs some work, sound fx when shooting and killing the scarabeus, some feedback on impact too. Also as the other comment said, some boundaries.
I also found a bug where my character keep moving on his own for some reason, and at some point i can not shoot anymore, the screen is overwhelmed with enemies and you cant shoot anymore but i dont see any number that indicates how many "bullets" i have left.
I liked that you have an "option" menu to turn down the volume of the music.
As the other comment said, a scoring system is needed ASAP as it would give some kind of objective as to why shoot the scarabs and also a way to give some meaning to consecutive replays, trying to beat your hi-score, etc.
Was this your first game? Keep at it dude, good luck!