Puzzle games live or die by their progression within the game and the puzzles themselves. If there is no satisfaction or great eureka moments from solving a difficult puzzle in the game you're playing, then chances are, you'll probably be too bored to even continue. Even if the puzzles are somewhat mediocre at best, if there no interesting hook or plot thread to keep prodding you along, then why even bother attempting to solve the puzzles in the first place?
Some games, such as The Witness for example, can survive on their puzzle design, mechanics, and beautiful aesthetic alone. Others, such as the Portal series for example, can maintain interest or curiosity from solid writing and a great sense of humor. Basically, mediocrity within the puzzle genre is death -- making it a pretty difficult genre to get right.
Thankfully, mediocrity isn't something that applies to Q.U.B.E. 2.
via destructoid https://www.destructoid.com/review-q-u-b-e-2-493857.phtml