I like the idea; it really appeals to my inner programmer and puzzle solver, and the first few levels do a good job explaining how the mechanics work. The simple art style also adds quite a bit of charm.
Once the game gets to real-time modifier switching though, there seems to be a nasty bug where the modifier icon will disappear if I move the mouse too fast, causing it to glitch out and forcing me to reset the level. Later levels get pretty time-critical about this too, and there doesn't appear to be a way to pause the level without completely resetting, so I just gave up after a while. If it weren't for that (imo game-breaking) bug, I would have really clicked with this one!