Using the sliding puzzles like that felt quite compelling, I like the idea! It was introduced very intuitively too, and I love the title screen using that design as well. I could imagine this being adapted into a larger game theoretically.
In practise, I think the concept is a bit removed from being really 'fun' yet, but I believe this could be ironed out. The platforming parts feel a little clunky: movement not super responsive, not enough coyote time, sometimes you can slide off a moving platform by landing funny. And when you fall and have to redo puzzles or just repeat a platforming element that doesn't feel that satisfying, it's frustrating more than satisfying.
The enemies in this vein only frustrate and complicate the more tedious part of the game.
I would suggest either not making 'falling' a real risk so that the level is more about being streamlined from one puzzle to the next. Or improving the platformer elements and introducing a diffeent way of handling two-sided puzzle boxes. I could imagine for example the interaction area turning into a button after completion, so you can choose to reset the puzzle to the solution you arrived at from that side, and same from the other side, and only have to do the actual solving once. These too could be enhanced with more in-depth platforming mechanics like double jump.
I made it to the waterfall puzzle and stopped at this point because I couldn't figure that one out.