Oh, that's what that is! I had found a similar thing making my own puzzles, "It's easy to make a puzzle you can't solve, but it's hard to make a puzzle that's

Oh, that's what that is! I had found a similar thing making my own puzzles, "It's easy to make a puzzle you can't solve, but it's hard to make a puzzle that's fun." Well, that' not entirely the same thing, but they overlap I guess.