That is very strange. The arrow keys and WASD should both work.
Do you have a gamepad plugged in? This game is not really meant for gamepads but the base-code I used has some gamepad support stuff in it. Maybe that is interfering with the keyboard controls somehow.
If that is not the issue, are there any other problems with the game? For example, are the animations playing or is it completely frozen? What operating system are you playing on?