I couldn't get survival mode to work, health goes down seemingly at random. There is no way of telling when reloading is about to happen. I cannot tell how to kill bosses or when they will be dead. Bombs don't always work, or if they do there is no way of telling. I was able to get through the zombie stage of level 4 simply by waiting, and I didn't lose any health.
The game barely works, and I'm afraid I'm in too bad a mood to look for redeeming features.