I think you probably need to have the controls explained. Also, I am not entirely too sure if this was runned on a actual GB rom, but the screen kind of looks like it's running on an emulator. I tried to press the Enter key, but it seemed to be mapped to the B button when I was looking at the screen device as well as the X key seemed to be shown as A button on the screen device, but the lasers only shoot at the Space Key. Also, the you might want to improve the Level 2 since the enemies ganged up on the player too easily.