Core Keeper makes the sandbox survival sim formula feel new

In Core Keeper, players are dropped into the center of a massive, procedurally generated cavern. From the heart of this cavern, you mine and gather resources: food to keep from starving, ore for armor and tools. You fight enemies and reveal secrets deep underground.

It’s a classic formula that will appeal to fans of base-builder survival sims, and the game sold more than 500,000 units in the first two weeks of Steam early access. I’ve been describing the game to friends as a top-down Terraria, though it has similarities to stalwart entries like Valheim, Don’t Starve, and Forager, with a bit of Stardew Valley as well. Core Keeper’s multiplayer (up to eight people), similarly facilitates a lot of collaboration and strategizing. But the game is far from derivative. It weaves tried-and-true survival sim elements into a tight play loop where the game is the grind in a way that feels meditative without being too repetitive.

Core Keeper feels like a dungeon crawler that you’re creating. You gather materials by mining square tiles, and for most of the game, you’re surrounded by walls that conceal explorable areas. The early game is basically just punching through barriers and filling up your pockets. This digging allows you to excavate different regions and grow the map. But the opening belies much more complexity behind the rocky walls. Like in Valheim, regions have big bosses, though it’s possible to play significant parts of the game while avoiding them. Some of these creatures are genuinely terrifying, but Core Keeper’s pixel art style makes the game feel homegrown.

Image: Pugstorm/Fireshine Games

It’s a familiar cadence: use resources to beef up your base, craft items that help you explore further, gear up for the boss fight, make secondary bases, and improve the return routes to key areas. As the paths you’ve created grow more convoluted, you can rely on your map, which you’re able to pull out as an overlay. And while bosses amp up the challenge, the crafting-focused sandbox design is suitable for people who are less interested in hardcore fighting and more interested in base-building. I’m only ten or so hours in, but I’ve watched Twitch streams where players have built extensive bases and crafted advanced items I have yet to even see in my playthrough.

All of this is bolstered by Core Keeper’s simple skill system. The more you do a particular activity, the more points you bank to spend on related perks. You choose a starting class, which offers bonuses — I decided to be a cook, which automatically gave me a cooking pot and some mushrooms. I chose this role because it looked cute, but the food-related stat bonuses are delightful. A certain type of spicy flower grants faster running, for example, and looks a bit like a burrito when cooked. Eating food is also key for filling up your “hunger” bar and staying alive.

This is an exciting amount of depth for a game that feels simple at first blush. Core Keeper does a great job of slowly revealing its crafting system, and the breadth of ways you can build up your base. You largely learn by doing — unlocking additional perks or finding new materials and wondering “What can I do with this?” — which is a rare quality in a genre that can be encumbered by many archaic rules and difficult-to-navigate screens. I also love those types of games, but I appreciate the streamlined simplicity of Core Keeper, which let me hit the ground running.

It all shapes up into a very inviting experience that teases dense design layers down the road. Even in early access, these feel like the raw materials of a multiplayer survival sim that will draw an enduring audience. I can’t wait to see how it keeps growing.