Over-all, pretty good. Graphics were cute. Not particularly challenging, outside some of the timing for toggling between worlds - hard to time a moving platform that you can't see. And there were a couple "puzzles", or at least interactions that either felt like they could have been either a "shoehorned" puzzle, or a bug, and I couldn't tell which (in particular a level where I couldn't jump up platforms but could 'clip" onto them, and the fact that I couldn't carry the rock over the button, that could have been a "puzzle" or bad collision detection with the buttons)
The last level was definitely tough, but mainly because of the bug that causes the player to get knocked off the pillars. Because the timing of the platforms immediately after is so perfectly unforgiving, there are many many chances to hit that bug. I didn't find that jumping helped much - standing in the middle seemed to be the much more reliable of the solutions in my case.
Also that last level kind of "breaks" the game logic. Starting when you get the world switching ability everything that changes has two states - then on the last level the pillars have multiple states (and maybe even differing numbers of states, since I could line then up differently on different runs?) That was obviously deliberate, but it violates the world model that the previous levels built for the player.
And please please please will developers stop assuming that players want to either slowly read the game story or skip it completely. Some of us read quickly, and get very bored watching text slowly appear.