I really like the zombie graphic. Here are a few suggestions:
1. Increase gravity. It feels a little floaty.
2. Maybe entering a door the down arrow key. You could later use enter, space or whatever else for another action or opening a menu.
3. Do not require pressing spacebar to go to the next scene. You could have the black screen set on a timer instead. Maybe 2 or 3 seconds to show the next room and then automatically go there.