Which bosses are in the current build
Two endgame fights are confirmed for the Early Access build, and they belong to the two routes rather than to a shared finale. The Gloom Worm closes out the caves. The Gunk Worm closes out The Facility, the route that was revealed in June 2026 and became playable at launch.
A fan database built against the launch build counts 76 enemies and lists 34 of them as bosses, with Gloom Worm V3 at 999 health sitting at the top of its health column. That database is a single unofficial source, so treat the counts as a useful shape rather than a specification. The same database records that 41 of the 76 enemies carry a reinforcement limit, meaning they can pull extra enemies into a fight while lane space allows.
The demo build had a single boss. If you are reading a guide that describes one fight in the caves with no mention of The Facility, it was written against the demo and describes an older version of the game.
The Gloom Worm, in the caves
The caves boss is the better documented of the two, and the reports on it are unusually consistent for a fight this divisive elsewhere. A player who has beaten both endgame bosses writes that the Gloom Worm is a sound fight built on risk and reward, with the only visual complaint being that the boss does not get the rainbow effect that normally signals a shield.
The reason preparation carries so much weight here is that you know which boss is coming. Encounters are laid out per route, so by the time you reach the end you have had the whole run to shape a deck for this specific fight. As one commenter puts it, you always know what the boss is, so you should be building around it.
That cuts both ways. The same fixed layouts mean later runs meet the same enemies in the same order, which a reviewer and a player both flag as the main thing working against replaying the game.
The Gunk Worm, in The Facility
The Facility boss runs in phases rather than as one continuous fight, and the first two phases draw the same praise as the caves boss. The third phase is where the same player report turns critical, and the specific complaint is a card rather than a mechanic: the phase hands you a card called Creeping Horror, which looks close enough to an existing card, Shivering Horror, that the two are easy to confuse.
The interaction that follows is worth knowing about before you see it. According to that write-up, Shivering Horror can discard Creeping Horror at random and deal 15 damage when it does, and there is no way to stop it. That comes from a single player account rather than a second source, so hold it as something to watch for rather than a documented rule.
On how often players finish it, a post in the Steam discussions puts the figure at around 8 percent of players having beaten the Gunk Worm. Completion percentages move as more people play, so read that as a point in time rather than a fixed number. The same player who wrote the phase breakdown beat it with over 400 health as the Janitor and still describes it as close.
What actually answers these fights
The advice below comes from the demo-era discussion of the cave boss, where the central problem was a curse card that raised the cost of everything in your hand. It constrained how many cards you could play per turn, which pushed players toward decks that win on one large card rather than a long sequence. The responses people found are listed here because the shape of the problem is what carries over, not the specific card.
- Forget the curse card
- Frog cards can remove it from your deck outright, which several players report as the cleanest answer.
- Exhaust it instead
- Escape cards consume the curse without needing a frog, so the cost is one card slot in the fight.
- Kill the appendages
- Clearing them yields more guts, which is what lets you keep pace without a single huge hit.
- Get the lock flail early
- Reported as an early pickup that makes the fight routine when combined with a small deck.
- Keep the deck small
- Fewer cards means a higher chance of drawing the one you actually need each turn.
Deck size is the through-line. Every response above either removes a card from the deck or raises the odds that the right card is in hand, which is the same goal from different directions.
- Decide which route you are committing to, because the two bosses want different decks.
- Strip the deck down. Cut anything you would not want to draw during the boss fight.
- Take the card removal you meet along the way, whether that is a frog interaction or an exhaust effect.
- Check the boss before you commit resources. The layout is fixed, so you can build for what is actually waiting.
Do not read a single strong run as proof the fight is solved. The same discussion holds both verdicts at once, with one player beating it on a first encounter with no trouble and others finding the cost pressure unbeatable. The split tracks whether the player found a combination that ignores the constraint.
Boss advice that may be out of date
Boss coverage for this game has a version problem, and it is worth checking dates before you follow any of it. The demo ran a single boss. The Early Access build runs two, one per route. Advice written in between may describe a fight that no longer exists in the form it was written about.
The practical check is the route. Early Access advice mentions The Facility and names two bosses. Demo advice talks about one boss and no facility, and the demo-era videos date to late 2025 while launch-era coverage starts in September 2026.
| If the source says | It describes | Confidence |
|---|---|---|
| One boss, caves only | The demo build | Community reports, dated to 2025 |
| Gloom Worm and Gunk Worm | The Early Access build | Confirmed by official hidden achievements |
| Curse cards raising costs | The demo-era cave fight | Multiple players in one thread, roughly a year old |
| Phased boss with Creeping Horror | The Early Access Facility fight | One detailed player account |
Balance changes arrive with patches, and anything about difficulty should be read against the build it was written for. The official Steam news hub lists the updates, and the dates there tell you whether a fight has been touched since a given write-up.