Cool game! I got to level 18, but I plan to get further. My one issue is the speed of the blade. I think it's set to track my mouse, correct? So I was able to set my mouse speed really high to go really fast or I could set it really low, and I could play a slow blade of destruction. I think what gets me is that the speed doesn't exactly transfer, so my slowest mouse settings make the blade unplaybly slow. Just wanted to point that out because some people are going to have different mouse speeds which will change how they experience the game.

I kinda think this can be incorporated into the game but as an option in the settings menu. (Though, I don't know how to even begin to set that up)

Another idea is to utilize the size of the game frame to get to the other side of the map. So if I move my mouse far enough to the left, slide up across my tabs and move back into frame from the right side, the blade jumps to the other side. That could make for some interesting levels. (You'd have to prolly make a dead space around the full screen version of the game for this to work)

Awesome work!