A shoot'em up game with limited movement. Might sound sound bad, but the good thing is the levels themselves are just another tool in your arsenal. You can break walls by shooting them or use them as cover. There is a base you have to protect from enemy fire, which adds an little element of strategy. However, none of that will matter if you manage to time the enemy spawn with your shots. But you still can be killed with one shots, so you can't let your guard down.