Oh yeah I like that idea! That would solve the problem that happens if you play very badly during your first run, and have to intentionally miss platforms etc. when tracking your shadow during second run. Also would solve the problem where there is an incentive during your first run to go slow so that your second run where you need to track your shadow is easier (or just always go back in time to never do anything twice during first run). You could explain this new approach as just part of the demon's spell - that user needs to mimic the demon.
Thanks for playing and the feedback!