I really liked this! it takes 2 simple mechanics (the reality switching and the slope momentum physics) and wrings them for all they're worth, combining slower puzzle platforming sections with high-speed action setpieces in a way that even some full-length 2D platformers can't manage. accomplishing that in a relatively short game is impressive. combine all that with a very well-defined and well-executed aesthetic, and you have yourself a very good game.
and i like that it's not afraid to be difficult or frustrating. there were times i had no idea what to do for a bit, and i know that might end up being a turn-off for some people, but to me that discovery is part of the fun. the physics definitely have a bit of a learning curve, with a slow base walking speed and a very high and heavy jump, but the levels are designed perfectly to complement what you're able to do, and moving around became second nature after a few levels.