How you're able to have that many objects on screen at the same time with that high FPS is beyond me. Could you try and, instead of making them move around randomly, just have them fall down?

I tried it myself but couldn't quite figure your code out.

Why did you post the same picture 3 times?

And how do you expect us to help you when you haven't posted any of the actual code for detecting collisions?

Also, does the energy of the boxes transfer to others on collision?