In our last big Toystore Update, we renamed and rebalanced all difficulties and made a change so that beating a level at Balanced difficulty (formerly Nightmare) now unlocks the next level.
This resulted in some players losing their progress if they unlocked levels prior to the Toystore Update by beating levels on the old Sanctuary difficulty.
With this patch, we corrected that issue so that now hopefully everyone has access to all levels they unlocked in the past.
We apologize to everyone affected by this issue and hope that with this update you can continue your observations undeterred!