This is a great game, I have no lag at all, its a bit easy, but gets challenging as you go deeper. I finally died in basement 5, I was out of machine gun and uzi ammo, I was surviving off my shotgun and pistol. I had at least 10 things of flamethrower ammo, but hadn't managed to find the flamethrower. As you go deeper, there are blue-ish zombies that take at least 3 shotgun rounds to kill. Great game, 5/5
I love this game. The only problem is that the weapons should be easier to find... I'm finding ammo for a machine gun, and I just recently found the Uzi.