Clearing a room

Killing a boss in the boss room, boss rush, hush fight, delirium, mega satan, dogma, mother and the beast, should all have highlights
Picking up items!

Using cards/pills/runes

Picking up dimes, nickels, golden pennies & lucky pennies

Losing mantle as any form of lost

changing floors (capture player as they go in trapdoor incase they skipped a floor)

Unlocks after victory (paper popups in game)

Most important though is room clear, boss clear & item pickup.