i can't get past the secondlevel
If you don't have any boxes to help you then try this:
Press E, P, or the ESC key to go into the menu. The thing is, there's an intentional bug. You can move while you're in the menu. EVERYTHING stopped in time. You should be able to stand on a button and press one of those keys and go through the door. The other levels should be easy then. But if you have a box just set it on the button and the door will open.