Time, Killstreak & No-Hit Doors

Timed doors appear in most biomes. If the door is not reached and opened within a set amount of time in a run, they will be locked and unopenable. Behind each door is some gems and jewels that become gold when picked up as well as some cells. Sometimes there also is a scroll.

The Prisoners' Cell
No timed door.

The Promenade of the Condemned
Door closes at 3 minutes, 30 seconds.

The Toxic Sewers
Door closes at 3 minutes, 30 seconds.

The Ramparts
Door closes at 6 minutes.

Old Sewers
???

Ossuary
Door closes at 3 minutes, 30 seconds.

The Prison Depths
???

The Black Bridge
No timed door.

The Insufferable Crypt
No timed door.

Fog Fjord
There are two doors in this biome: One in the collector's room right before it that closes at 10 minutes, 30 seconds and another one inside a building that closes at 15 minutes.

Graveyard
???

Slumbering Sanctuary
???

Forgotten Sepulchere
Door closes at 10 minutes, 30 seconds.

The Clock Tower
???

Clock Room
No timed door.