Fantastic co-op sandbox Core Keeper is adding an explosive new biome and boss for free

We're spoiled for choice when it comes to the best sandbox games that you can play with friends. But while it's easy to fall back on big names like Minecraft, Terraria, and Stardew Valley, I'd recommend gathering your group for a few sessions of Core Keeper. Launched out of early access in 2024 to a 94%-positive Steam reception, it's a very worthy addition to the collection, and it's about to get even bigger. Developer Pugstorm has just unveiled its next update, Void and Voltage, which adds a new biome, dungeon, and boss to discover, and it'll be arriving for free in January.

The quick and dirty way to describe Core Keeper is probably to compare it to Terraria but as a top-down game with a perspective akin to Rimworld or Stardew Valley, but that still sells it short. The core loop of exploration, combat, uncovering items, crafting gear, and battling bosses is absolutely the kind of compelling that makes hundreds of hours melt away before your eyes, especially if you're playing it as a co-op game. But if you thought you were done with your adventure, think again.

"Those of you who have made it to the outermost regions of the underground might have thought that you'd reached the end of the world," Pugstorm teases. "Well, that's the thing about ancient underground caverns… Just when you think you've explored everything, something new and exciting crops up on the horizon."

That something is Breaker's Reach, a totally new biome that's "bristling with untold secrets and inorganic life." Immediately, you'll spot the mechanical nature of much of this region, meaning fresh threats and opportunities in equal measure. Getting your hands on all those valuable components will mean battling your way through chargers, patrollers, swarmers, and a gigantic new boss called SAHABAR, described as "a machine straight out of your nightmares with laser-targeted energy beams and special abilities that'll put your timing to the test."

Manage to overcome all that, however, and you'll be well rewarded. I'm most eager to put the new automation tools to the test, which include a workbench called the Advanced Automation Table. This is packed with recipes that can help you with gardening, salvaging, and item disposal. "There are oodles of new automation systems and electronics coming to Void and Voltage, such as new generators, critter catchers, proximity sensors, and more," Pugstorm reveals.

Of course, there's plenty of gear up for grabs as well. The handheld flamethrower will likely be a tremendous asset for dealing with enemy swarms, although be careful about what else you tag with it. Elsewhere you can expect miniguns, mortars, grenades, remote detonators, more decorative items, extra armor sets, additional off-hand items and accessories, and even another minion and tome.

That's still not all, however. Down in the underground, tears in the fabric of spacetime itself are unleashing a new sub-biome, the Void. This region is filled with newly evolved variants of many familiar enemies, with "a never-seen-before combat mechanic allowing them to make special attacks such as explosive flames, spinning arcane beams, and lightning orbs." Make sure you're well-geared before you step up to the challenge, then.

Rounding out the update are some other community-requested features, including echo maps that can be used to locate specific key areas around the world. You can also look forward to "six new crafting statues with waypoints, a whole host of new scenes, new achievements, new paintable items, minion improvements, the ability to break previously indestructible items… the list goes on."

The Core Keeper Void and Voltage update launches Wednesday January 28 as a free download for all players. While there's still a couple of months to wait, now's an ideal chance to jump in, because you'll have plenty of time to work your way through the main progression and prepare for your journey into Breaker's Reach.