Thanks, glad you liked the ending. Agree with the critique, something like this was planned it the initial concept, but we had to cut the scope quite a lot. There should have been a mini boss that you had to beat to access each of the thread balls.
The fastest way to reset is actually to just exit to a main menu, and start the game again. The progress will be saved. This is not obvious though and a respawn button would take literally a minute to implement, so we definitely should have thought about this.