The next sign that all is not normal here is that practically anything you do with your character winds up killing him. Try to do something with a rock: dead. Try to touch a barrel: dead. Try to touch a tree trunk: dead. Try to walk where you shouldn't: dead.
The third and last clue that you're playing a special game is found in the death screen, which shows a series of blinking images in an attempt to bother you as much as possible, along with some accompanying music.
House Death is as frustrating as it is entertaining. It may often seem unfair, but in exchange you get some truly funny situations. To really enjoy it, we recommend playing it together with a friend or two.