Yeah. I ran out time and didn't really get to finish or playtest it, so it's a little buggy XD. The point of the blue stuff was actually to progressively "go back in time" to the beginning of the level. The story is that you got to the boss door, but you forgot the boss door key which is at the beginning of the level. However, there are gates that close behind you, so you have to collect "past pieces" to progressively get there (and get some key items along the way). There was probably a glitch that let you pass through the gate, though. Whoops!
Edit: If you want to play a version of the game that is less buggy, I was able to do a late submission, which fixes the worst of the bugs. The url is: https://temporalthunderstorm.itch.io/back-to-the-start-window-res-made-smaller.