Pugstorm has released Core Keeper 1.3, titled Riders of the Underground, as a free update for the mining sandbox adventure. Publisher Fireshine Games says the September 21 release is available on PC, Nintendo Switch and Switch 2, PlayStation 4 and 5, Xbox One, and Xbox Series X and S. Its central additions are rideable cattle, a hookshot for crossing gaps, a new Moss sub-biome inside the Forgotten Ruins, several pets, equipment, and quality-of-life changes.
This is an expansion of movement rather than a separate campaign. Core Keeper already combines mining, crafting, farming, combat, base construction, and exploration in a generated underground world for one to eight players. Version 1.3 changes how players move through that world and how existing animals fit into it. The update announcement confirms the features and platforms, but it does not quantify map size, traversal speed, or the amount of new equipment.
Existing cattle become controllable transport
Friendly cattle can now be ridden, named, and assigned behavior. The announced options let an animal stay in place, roam, or accompany the player. That gives livestock a role beyond a base enclosure: a mount can become part of an expedition while still being managed as a persistent creature rather than a disposable vehicle.
For players, the practical questions concern the complete journey. A faster route outward only helps if the animal can be kept safe, parked predictably, and brought home without disrupting combat or gathering. Pugstorm’s behavior commands address the parking and companionship problem at a basic level, although the sources do not publish comparative speeds or explain how every terrain type affects a mount. Players should test a short, familiar route before taking valued cattle into dangerous territory.
The hookshot changes a familiar building decision
The new hookshot lets explorers clear chasms and pits without first laying a bridge or path. In a game where travel often leaves a permanent constructed route behind, that creates a meaningful choice: spend materials and time on infrastructure that anyone can reuse, or equip a traversal tool for a quicker crossing. The second option is especially relevant during initial scouting, when a player may not yet know whether a distant area deserves a maintained connection.
The distinction also matters in multiplayer. Core Keeper’s Steam listing confirms drop-in and drop-out online cooperation for two to eight players. A bridge is shared infrastructure; a hookshot may depend on who is carrying the tool. Groups can avoid unnecessary backtracking by deciding whether an expedition is reconnaissance or route building before leaving the base. That is an editorial recommendation based on the announced mechanics, not a new rule stated by Pugstorm.
Moss and pets add reasons to revisit the Forgotten Ruins
Riders of the Underground places a Moss sub-biome in hidden parts of the Forgotten Ruins, adding greenery to the stone environment. The update also introduces multiple pets with distinct abilities, plus weapons, accessories, and armor. Neither inspected source provides a complete item list or spawn table, so players should treat discovery and balance details as something to verify in the installed build rather than infer from the launch summary.
The update offers a useful design lesson for small sandbox teams. New movement tools can refresh existing geography without requiring every addition to live on a wholly separate map. Mounts change travel time and attachment to animals; the hookshot changes which gaps are barriers; a sub-biome gives established ruins a new search target. Because these systems overlap with old saves and cooperative play, their quality will depend on edge cases such as follower pathfinding, dismount locations, gap detection, and players arriving with different equipment.
Before a long session, players should confirm that the game has updated on their chosen platform and back up any locally managed saves permitted by that platform. The confirmed proposition is straightforward: version 1.3 is free, reaches the announced PC and console families, and expands traversal, pets, loot, and the Forgotten Ruins. Claims about how much faster exploration becomes or which additions dominate progression require play beyond the release materials.