I manage to play your game, and it reminds me of the classic arcade Space Invader meets Galaga and Raiden. If I suggest into include the option for the player to switch button control for the game. Especially, if the player does not have a mouse button for the PC. The final suggestion is adding the satellite, about two for each side of the ship for the player to acquire whenever shooting an enemy to unlock, that is similar to classic shoot' em up games. I hope these suggestions would help your game.