Loved this game. Its controls were really fun to interact with, and the overall game feel was on point (with the screen shakes, sounds, particles effects, trails, etc).
One small thing is that I did not realize at first that the thing that moves (I'll call it Dobby) would continue following my mouse cursor even if I let go of the mouse key. My poor hand suffered from having to keep the mouse pressed until I reached the goal so I was internally screaming a lot ;) Also I didn't know that Dobby would not move past the mouse cursor. I guess you can communicate how Dobby's following mechanic works by letting the player start each level by placing their cursor over Dobby (instead of by clicking).
One thing worth noting: I probably wasn't guiding Dobby the way you intended, but when I first got to the level with sharp turns, I would wait for Dobby to arrive at a corner then suddenly swipe my mouse to make it turn. That felt good! I felt as if I was a wizard manipulating a projectile's trajectory telekinetically. I don't think this game would necessarily benefit from having a narrative, but you could certainly use this game's mechanics in some other large-scale wizard-based project. (I'd also tweak the controls to emphasize a tossing-projectile sensation)
You probably intended this, but I could skip a couple levels by going around the maze. Some levels were a bit too long for comfort, but I know that's part of the challenge. Anyhow, loved the idea of this game. Keep on being awesome!