Thanks! I'm glad you enjoyed the puzzles and felt the difficulty increased at an appropriate rate. I'm definitely seeing that the mechanics of the dangerous tiles (red and spikes) weren't introduced sufficiently well for many people, and thereby there was some confusion about how they worked: something I'll try to keep in mind for the future, of course. I will say in my defense that I tested all the levels before submitting, and they all should be possible, though level 10 does feature a unique challenge where the knights must be in the proper position before you leave the starting area.