I've gotten partway through the third level (sewage water level), and unfortunately I had to stop.
It's definitely an enjoyable game, with well-designed levels (at least as far as I've gotten), nice-looking graphics and good music, and overall a pretty good playability. However, I'd say that the game misses the mark somewhat with the intent to be a "laid-back" experience. The graphics and music definitely put it halfway there, but there are definitely ways in which the level design isn't forgiving enough to be calming. There are some points at which the collection of cubes, or even the restarting of a level stage (I suppose you could call the parts of each level "stages"?), is left up to a 50/50 guess as to which way to go. Likewise, there are also some points at which the player will be sent back to the beginning of the stage many times, due to imperfect timing with sequences of size changes and jumps to avoid hazards. I would say I'm one of the calmer gamers out there, but eventually I had to say that I'd played enough before it got annoying. I can imagine it would be even moreso for others.
Tiny detail as well: I kinda found the differences in graphics detail and style between the title screen/instructions screen and the actual game to be a bit jarring - I had been expecting a game that looked like the title screen and instructions screen. Considering that the initial room of the level select screen (with the light-up letters) and the player almost look like a stereotypical beginner platformer project in their design (not meant as an insult, it's just similar design trends), this might leave some players feeling like they've been given a bait-and-switch, and quit before they even start playing this interesting game.
That being said, I definitely had a good time playing this game, and I think it has a really well-thought-out concept behind it. There was nothing inherently game-breaking, and the fact that even the case of being stuck in a wall was accounted for by the developer impressed me! So I'd have to say that this was worth my time!