Thanks for reviewing my submission!
I agree the gameplay is a bit unintuitive. For the future, I might refrain from trying to do a 3D game if I have only 2 colors to work with as trying to figure out just how to portray things and make sure there is some sense of space and distance took up so much time I never got around to really strengthening the gameplay!
I imagine the lag might be because the garbage collector is disposing of all the bullet objects shot from the big gun ships. It was only after submissions had concluded that I realized I should have just used object pooling instead of instantiating and destroying so many small bullets! Lessons for the future at least.
Either way, thank you very much!