It's exactly as advertised. It involves many levels based on the same mind-bending concept but with varying structures and complexity. It's also quite simplistic, with no fancy sound effects or distracting visuals and no annoying ads (at least as far as I have played, which is ~40 minutes) The only reason I don't give 5 stars is because it's too simplistic for my taste. The levels begin to feel repetitive. It's the same concept over and over.

EDIT: this doesn't count toward lederboard or achievements even though it claims it does. This is solely puzzle. Don't expect graphics out anything else. Once you understand the logic behind these they start to become easier to complete. Could have slightly made it more difficult by limited moves, rank by moves, or something as such. Good for wasting time so for a little bit of currency it is a good choice.

In an age where every game wants to hit you with an ad per level, useless fake currency, daily login gimmicks, and all the other monetization models, it is truly refreshing to have a pure, fun, no distractions puzzle game. The game itself, very relaxing, great art style, perhaps not the most challenging out there, but it doesn't need to be.