Underrated game. I've always wanted a game about changing timelines, but was concerned about them being uncontrollable. The merging concept is brilliant. The fact that I can choose whatever part of the snapshot I wanted to keep and there are rules for keys whether they should exist or not in the timeline is a nice touch as well. I love the optional challenges as well. The puzzles themselves are not too hard nor too easy. They are balanced which makes them engaging.