Man this game simply blew me away. A great concept that not only obviously fits the theme very well, but also makes for some really clever and mind-bending puzzles, and it's a whole lot of fun all on it's own too, especially because it is so well-executed. With that I mean that even if there was just a single level with no goal I'd probably enjoy moving around in it just to perfect my slug walk, try to move around and spin symmetrically, and watching the beautiful colors fading together.
I don't really have anything else to comment on, really. It's all great: the movement, the clever and varied puzzles, the "inner workings" such as the collision detection and whatnot, and the very appealing art style, which is fittingly minimalist for this kind of game (and game jam time limit), yet has a lot of subtle color variations in the background, a clean and attractive GUI and some really smooth animations (along with the SFX) that really add to the readability and enhance the communication between the game and the player.
I actually played the game once with each color combination just to look at all the subtle details some more, and I still can't decide if I prefer grape purple and lime green, my favorite combination, or the blue and yellow combo which creates a gradient that reminds me of this one specific ice cream wrapper, which was so gorgeous that I still credit my decision to get into the design field to this day.
Anyway, I smell a top-rated game here. If this ends up being one of the highlights of Mark's video later, remember that I called it.