Reminds me a lot of old flash games I used to play as a kid, very nostalgic. It can be brutally hard especially if you don't use your ammo efficiently and I feel like some of the unlockable weapons weren't quite as good as the starter rifle. I think it would have been nice too if the ammo for each gun was separate to encourage switching more. Still it's a good basis for a little "time waster" game that gets progressively harder.