I really can't like this game
As someone already said I can't understand why you can't shot 360 degree. Besides that I can't find funny a game you just run firing waiting for a lucky power-up wich last a couple of seconds. If there was any kind of upgrades or skill points, but there's not.
I'm not saying it's a bad game, it's not. It's a cool game, a lot of people do like it, but i don't.