I know the problem you described in the last paragraph very well. Have you set the collision detection on your rigidbodies to "Continuous"? If not, do it. This will maybe solve your problem.
Thank you! I will give it a try.
Currently I think it is because I made two levels in 1 scene, and there are too mamy moving parts.
Should not be a problem. Does all moving objects in your scene have a RigidBody2D on it? If not, you should do it ;)
I put everything on Box Collider 2D, so that probably is an issue. It seems to work though, so long as frames aren't dropped.
