Ya, adding [ESC] as am exit was something I added as a quick fix at the start and got used to it through so many play tests that I didn't realize it was a problem, but in hindsight that is the key you'd use to deselect. Probably should've just added an exit button in the corner, would've taken a similar amount of time to add.
Otherwise thanks for enjoying it. I'm glad people seem to like the tutorial since it's what I put most time into.