Lasers

Thanks to everyone for the useful feedback on my Laser game so far. I have added another three levels, making a total of ten. I am trying to order the levels in increasing difficulty. However, I am having trouble comparing the difficulty of levels (since I already know the solution to levels when I design them, it is hard to judge how hard it would be for someone else to solve them). It would be great if I could get some more feedback on if you encounter an earlier level which appears to be more difficult than a later level.