A rudimentary map to show the rooms you've been to, and the doors you haven't explored.
Permanent transformations that don't time out, i.e. be a plushie forever (unless you squirm/resist), or a pool toy (squeak enough times)
Guaranteed boss in the floors they're available, if they're not already guaranteed.
A "Surrender" button.
Edit: A trapped box/mimic. Get in, get into a scene...