Seems like a decent concept that was pretty fun, but a little clunky and confusing with its execution to me. I definitely did like getting past all of the various traps and obstacles and then running back through a more challenging version of them: pretty cool stuff. There was some minor jank here and there with hitbox confusion and such, but for the most part it was fun.
The weirdness came to me with the toolboxes and bridge implementation. On one hand, I feel like I understand the idea is that you can strategically choose what bridges you want to build in order to skip some challenging parts of the level. However, for the most part you are given so many toolboxes so easily that it becomes not a choice, but a foregone conclusion that you can just skip huge parts of the game. I'd prefer if the toolboxes were either scraped altogether so as to make people experience the whole game, or to be either severely limited so you need to make a strategic choice of what bridge to build and what bridge to neglect, letting you only skip one part of the level over another. Additionally, you could make it so that the only way to get toolboxes is from challenging branches of the level: then you'd need to decide if it's worth the risk to go through an optional challenge for a toolbox to make your escape easier, or if you just need to get better at the required parts of the level and not skip them. Just feels like the concept wasn't fully thought out and executed in a positive way, at least to me personally.