Boiler

Arena 4 of 6 in Blood Dungeon. We have not played far enough to describe the layout, enemies, or a boss name for it. What we can show is verified from Steam's achievement data.

Steam achievements Read Aug 26, 2026 UTC

Getting here

You reach Boiler by defeating the boss in Corridor. That kill grants the achievement “Boiler” — named after this arena, not the one you just cleared, because it's what that fight unlocks.

Players who make it this far

34.3%

Defeat the first boss in Corridor

Where this sits in the run

By the time a run reaches Boiler, only 65.7% of players have already dropped off — those who didn't beat Corridor's boss never see this arena. A low unlock rate on a later arena mostly means most players haven't reached that far yet, not that the arena itself is unusually hard. We are not making a difficulty claim from this number, and it is not a strategy guide — it's a population count.

Achievements that mention Boiler (5)

Achievement	Condition	Unlock rate
Boiler	Defeat the first boss in Corridor	34.3%
Tombs	Defeat the first boss in Boiler	26.9%
Multiheal	Fully explore Boiler	21.5%
Hypnomancer	Defeat the second boss in Boiler	5.7%
Kill Zone	Defeat the final boss in Boiler	3.2%

What we don't have: a boss name, a map layout, an enemy list, or any strategy for Boiler. We haven't played it enough to describe those honestly, so we're not guessing. The numbers above are the only claims we're making.