Great up until levels 6-8, where as you sweep, you miss pixels for no apparant reason. During level 8 it's nearly impossible to stay alive because most of the pixels phase through your tree. Great game otherwise.
The game is nicely designed, but the randomness of it really made this a chore to complete. I can understand there being a few different ways for guards to move through the level, but the way the guards and target move around, every level tends to come down to nothing but pure luck. If the game were more focused on how skillful you were at timing your dashes so that PATROLLING (instead of wandering, as you have now) guards didn't see you, it would be much more fun, and less frustrating.