I know :-D.
I property have "Light", "Easy" and "Medium" as areas in the light version. and the whole game is not that hard as the original Xor was, or near that. So its a causel game or so close on that as possible (howover getting 4 stars can sometimes been hard, but 2 and 3 is often possible with regular gameplay). So exists levels would not been harder in the light version, and when I change them, they would been a bit easier or the levels area is a bit smaller.
So in the final, I dosen't try to create near impossible levels, nor very big levels.