First, I love the concept. Can't remember seeing something quite like it before, but this feels like it could be super addictive. A bit easy at times, but I only played the first ten levels, so that's not a problem. Also, the first couple of levels worked really well as a tutorial

One thing that annoyed me was that whenever I finished a level and I just wanted to keep playing, I had to move my hand from the keyboard to the mouse to click a button. I would love it if you had keyboard shortcuts for starting the next level.

But that got me thinking, and I realized that the one problem I *really* have with this game, the one thing that stands in the way of me getting completely addicted to it ... is that it's not a mobile game. If I had this on my phone, I could definitely see myself sinking a lot of time into this. Make the floor tiles surrounding the sticky cube clickable/tappable so that I can control the whole game with my fingers, and this would be a ton of fun.

Two character mode was okay, but I don't really see the point of making it a separate mode. It's not a two PLAYER mode, so it's not THAT different from the main game. In my opinion it would make more sense to use the two player gimmick as an additional puzzle element in later maingame levels. It should be more self-explanatory, though, so I don't have to read how the level works. I'm guessing these are temporary graphics, though, in which case the final graphics should do a lot of that job for you. If there's a big flashing button that looks like it can be pressed, it will be tempting to press it, and if the other blue box looks more like a closed door or a set or iron bars or something, it will be immediately intuitive that "I have to find a way to open that - maybe I should press that button over there and see what happens".

While I love the casual aspect of this game, it could be interesting to see what would happen if you added a couple of more "stressful" levels. Like a level that has to be completed before a timer runs out, or a level where an enemy is following you and trying to eat you (either turn-based or time-based), or levels where parts of the floor crumbles after passing over it once. Probably best not to overdo it, but if every fifth or every tenth level was a challenge level, it would definitely make the game a bit less monotone.

The one "bug" I found I assume you already know about: Clicking "Credits" takes me to a blank screen with no "Return to menu" button.

nice concept, I would like to try another level  ^^

I'm curious ro see what you can bring to the course like obstacles, traps or bonuses.