Controls are standard for a game of this kind. You can carry 4 weapons at once. A knife, grenades, a pistol and one main weapon. As you defend against the zombies different areas will open up and you can get additional weapons in those areas. Hit 'E' to swap weapons. The menu is fairly straight forward. Half in English. I just changed the resolution to 1920x1200 and set it to "high". According to fraps I was getting about 40~ frames per second. It's a decent looking game.
The game progresses in rounds. After you clear all the zombies in the round a new round will start. There does seem to be a time component as well. If you don't finish one fast enough and there is one or two stragglers it will start a new round. There are a few "boss" rounds where there are some very tough zombies. One of the most difficult I've found so far is round 20 where there are 3 or more chainsaw wielding zombies. They're very tough and the second time through I didn't pass them. The game can go on for up to an hour. I assume, I haven't gotten past about 30~ minutes so far. You have 2 extra lives to help you last. Some zombies will spawn with guns later on, and zombies will have various speeds and toughness mixed together. Sometimes they will be both fast and strong. you want to be fleeing and dropping grenades or shooting backwards at that point.
The pathing is a bit off in this game. There is a spot where you can stand, pictured below, where if you step through the doors most of the zombies will turn around and go back around the other way. If you're in a bad way it's a good spot to exploit the AI and pick off a couple and step back through causing them to turn around. This does not always work. I would say only about 70% of the time so far. If zombies are close to you they will follow you through and the odd one will charge through anyway, so don't completely rely on this trick. It's pictured right and you can see me exploit it at the end of the video. If your health is below 25 when the round ends you'll be bumped to 25. Zombies will drop ammo boxes and med-kits. Med-kits seem to heal around 50%. Other than that, there is another bug where zombies will just walk over stuff, including debris. There is fire on the stairs. Don't try to jump over it you won't make it and you'll die fast. You cannot use the fire extinguisher you find in one hallway near the trick corner either. Trying to open it does nothing and it's very explosive. After the 20th level you need to head upstairs or you'll catch on fire.
All in all it is a pretty fun game. A good time killer. I'm hoping to make it to the end sometime and see if there is anything special there or not. I just need a good strategy for the chainsaw zombies.