The earlier levels were fun, but then it started to turn into a trial and error type thing for me. I realized around level 16 or so that every piece was being used, so I started just looking to configure the board in a way where no flat edges were exposed. I was able to complete the levels until 22 this way, then I got stuck because there was more than one way to configure the board that time, haha. I quit after that level because it was just too complex to be fun at that point.
Something to remember, every level in a game doesn't have to be more complicated than the previous one! You can level off a bit after the game gets going. This keeps the levels shorter, and you can make more of them - which gives the player a better sense of progress. With a game like this, once the board gets past a certain level of complexity, it stops being a puzzle and turns into a guessing game, which is never very fun.