An interesting concept, though I'm not sure if everything was working as it should. I was initially a bit confused about what I'm trying to do, until I reread the instructions.
However, I'm still not sure what the purpose of the sword wall thing is; eventually I managed to beat the level by focusing only on making a path that covers both gravitational sides, and the sword bits seemed unnecessary, so I just ignored them -- the knight walks forward regardless.
I'd also have liked some reaction to the knight flying off into the void if I haven't put a block down. It seems to make the game unwinnable, since there doesn't seem to be a collider up there, so maybe a game over at that point would be useful?