It was fun blowing up a few undead baddies. I like that you actually gave a control guide on the opening screen. That's not something I think should be part of a finished game, but on these wip type projects, it makes user testing much easier.
There is 1 thing I think needed a little more clarity up front. The open page said to open doors, press middle click but didn't give any information on what a door looked like. The first time I got in, I couldn't figure out how to get out of the starting room. A few times I even tried to blow a hole in the gray wall. After trying, I restarted to look and see if there was something I missed. It was in rereading the directions that i started to wonder if that big gray block was a door.