PC Gamer previewed the update in a trailer shown during PC Gaming Show Tokyo Direct, while Pugstorm’s earlier Steam announcement established the wider feature set and the September 21 release date. The update is also planned for console versions, but the practical headline for Windows players is that the same 1.3 release is due on Steam and the Epic Games Store.
Cattle become customizable mounts
Every cattle type in Core Keeper will become rideable in version 1.3. Players use a new Saddle item on a cattle creature, then can ride it rather than treating it solely as a farm animal.
The developer has also said mounts can be named and assigned a behavior when they are not being ridden. They can be told to remain in place, follow the player, or roam. Removing the saddle returns the creature to ordinary cattle behavior.
This is more than a cosmetic addition for established saves. Core Keeper’s worlds can grow large as players push outward from the Core, excavate tunnels, build rail systems, and maintain distant farms or resource operations. A personal mount gives players a flexible movement option that does not depend on laying tracks or carrying specific transport infrastructure into every new area.
The trailer also highlights Orex, a dinosaur-like cattle type associated with the update’s new Moss area. Whether all mounts share the same movement traits, stamina rules, or combat limitations has not been detailed ahead of release, so players should wait for the full patch notes before planning a particular farm or exploration build around a specific creature.
The Moss sub-biome and new threats
Riders of the Underground adds the Moss sub-biome, described by Pugstorm as a lush and non-hostile area. Its calmer framing suggests it is intended as an exploration and resource-gathering contrast to the hostile territory surrounding much of the game’s progression path.
The trailer also shows a trio of large, snake-like hydra enemies erupting from sand. Pugstorm has not yet published the full mechanical breakdown for those enemies, including their spawn location, loot, or whether they are bosses. A mysterious sealed doorway appears at the trailer’s end as well, but the developer is intentionally holding back what lies beyond it.
That restrained approach is worth keeping in mind: the trailer is a feature preview, not a complete changelog. Players can count on the new mounts, Moss sub-biome, Orex cattle, Hookshot, pets, and Mage and Summoner work being part of the announced update. They should not assume that every shown location or encounter will be immediately available at the start of a new character’s journey.
Mage and Summoner players should wait for the detailed notes
Pugstorm has confirmed improvements for the Mage and Summoner play styles, along with new gear and pets, but has not publicly laid out complete numerical changes before release. That means it is too early to call this a broad balance overhaul or advise players to abandon a current build.
For returning players who favor magic or summoned allies, the sensible move is to update first and read the launch notes before reallocating talent points, discarding equipment, or starting over. The update may expand options for those styles, but the announced material does not establish exact changes to damage, mana use, summon limits, or item progression.
Existing worlds should remain usable, with one caveat
Pugstorm says it aims to make major updates playable in existing worlds. According to the developer’s community guidance, some new content is added automatically to older worlds, while certain features may require players to opt in when using a world created before version 1.3.
That is good news for co-op groups with long-running servers: a fresh save should not be a blanket requirement. But hosts should back up important PC save data before applying a major update and check the in-game world options after launch, especially if a group wants access to the new biome or related generation content.
Players should also make sure everyone in a multiplayer group has updated to the same version before a planned session. The new content itself is releasing across PC storefronts, but Core Keeper does not support cross-platform play between PC and console families, so a Windows PC group should not expect to join friends playing on PlayStation, Xbox, or Switch.
What to do when version 1.3 arrives
- Update Core Keeper through Steam or the Epic Games Store on September 21.
- If preserving a long-running world matters, create a backup before loading it under the new version.
- Check the update’s full patch notes before changing a Mage or Summoner build.
- Load an existing world and review its available options for any new-content opt-in choice.
- Keep multiplayer players on the same game version and within compatible platform groups.
For players who have been waiting for a reason to revisit Core Keeper, Riders of the Underground is a substantial movement-and-exploration update rather than a small collection of cosmetics. Mounts and the Hookshot should change the rhythm of travelling through the underground, while the Moss sub-biome and unrevealed late-game content give returning groups new territory to investigate once the update goes live.