Good design, and clever thing with how to activate the laser receiver. However, eliminate the stuck point where the weighted cube is. If you can fit a laser field in there some way to signal people not to go in there, that would work. Not sure it's possible though with all the glass around it.

Arrrggg I just can't get the laser lined up, such a failure.. /cry

Managed to beat it now, really loved it, you just have to know that it's a very bad idea to jump down to the first cube.

I got stuck in the room with the cube, no way out of there when you fall down.