I'm not sure if I'm missing something or something isn't working correctly on my end but I can't get the door to open on the first level. I've tried WASD keys to walk into it, clicking the handle, jumping. I literally can't get the door to open to continue the game.
From the very little I played though, its a cool concept for a game and I wish I could play more than the first level lol :'(
Edit: Its a lot more fun when you can play more levels. I will say though that the acceleration level was oddly difficult; I kept falling through the board instead of going up but I did get past it.