let me start of by saying i write all my games in straight javascript(which is more about learning javascript then making good games) so i don't understand the problems with Fusion. Your enemies randomly respawn and move way to quickly. the art in this game is inconsistently bad, i get it your not an artist but maintaining a consistent style even if its a bad one is better then this. I use pixel edit its like 10 dollars and a great piece of software. Personally for a shooter game i much prefer wasd over arrow keys but it may be different for left handed people so if you can just make both work. This is a good start it needs a lot of work but whos game doesn't. Next time spend more time on the art and getting ride of as many bugs as possible.