My favorite moment was realizing the interaction between the arrow block and the Möbius strip. It was not immediately clear to me how it would help, and then when I realized I could "flip" the direction of the arrow even though relative to myself it never changed, was a brain-mini-exploding moment and I really cherish that. You're really onto something with that.
Screenshot of me moments before brain-mini-explosion:
I think the level right before the arrow block is introduced is too tedious though. It does require you to loop around, but it effectively doesn't matter that it's a Möbius strip.
The level after the arrow block is introduced is also tedious. It kinda teaches you how stacked blocks interact (I personally find it unexpected that the blocks "slide off" each other and it would have been easier if they had some friction), but once you learn how that works it's not used again, and it takes too many moves to shuttle the arrow block to the right place. I think I would have been willing to do it 3 times max before feeling annoyed. Maybe more if a pushed block could push further blocks.
I eventually understood how the time travel works, but I think the ticking clock was throwing me off a little because the fact that it ticks at a constant rate implies there's some real-time element to it, but really it's all still turn based. There's some incongruity in my head though because I feel like the player character should be going backwards in the time-reversed zone too. Have you thought about reversing the block pushing into block pulling in the time-reversed zone? The blocks wouldn't move on their own in that case. When you cross into the time-reversed zone, your character's orientation (if that was displayed in the game) flips as well (the same way a spatial Möbius strip mirrors you across the major axis when you cross the splice point) so it would look like you walk into the boundary facing forwards and come out the other side facing backwards. In this hypothetical I'm using character orientation as a shorthand for time direction. Even though the character would be moving backwards, you'd still control it as if you're moving forwards. I haven't thought this through all the way so maybe there's some problem with this premise when it comes to designing puzzles around it.
Like how the arrow block creates an interesting interaction with the standard Möbius strip because it depends on the direction of the flipped axis, maybe you could explore objects that behave differently depending on the direction of time, like a cliff that functions as a one-way door.
Very creative and inspiring idea and excellent tutorialization. Keep up the good work!