Ymmv. Personally, I tried out about 20 levels, most of them in the “hard” set, and I realized I was still waiting for the game to get interesting.
The background music is nice, the type of puzzle is new, it’s aesthetically pleasing, as far as I can tell it’s not buggy or anything. And I appreciate the payment model — free with ads, or pay a small one-time fee for extra content and no ads.
It’s just that it never took me more than a couple seconds to figure out how to solve each level, once I understood the rules. And because each puzzle is so small, it’s not even useful for just zoning out and playing a while. It’s a couple seconds of play, a couple seconds of win screen, repeat.
If the same company makes an app with a different type of puzzle that’s more challenging, I’d be willing to give it a try.