4J Studios, the Scottish developer famous for the monumental task of porting Minecraft to consoles, has transitioned its new sandbox project into a more public phase. After nearly a year of closed testing, the studio’s open-world builder, Reforj, is now available via the Xbox Insider programme.
The move marks a significant milestone for the Dundee-based team, shifting from a restricted “Pioneer Program” to a broader audience. While the game remains in pre-alpha, the Xbox Insider release allows a much larger pool of players to stress-test the proprietary Elements Engine and provide feedback on the procedural voxel worlds.
Built on a custom foundation
Unlike many modern sandboxes that rely on off-the-shelf engines, Chris van der Kuyl and Paddy Burns have opted to build Reforj on their own tech. The Elements Engine is designed specifically to handle the demands of high-fidelity voxel manipulation, offering sculpting tools and architectural flexibility that go beyond simple block stacking.
The current pre-alpha build features diverse biomes, multiplayer functionality, and community-influenced content. One such addition is the Stalac, an ore-consuming mob that originated from player suggestions. This focus on “player-studio collaboration” suggests 4J Studios is leaning into the community-driven development model that made its previous work so enduring.
A lost civilisation and exotic voxels

In its current state, Reforj tasks players with exploring exotic landscapes to uncover the remnants of a lost civilisation. The gameplay loop balances creative expression with survival elements, though the primary draw remains the “sculpting” mechanics. These tools allow for more organic shapes and intricate décor than the rigid grids typically associated with the genre.
The game is available for free to members of the Xbox Insider programme. As a pre-alpha title, it is expected to receive regular updates as 4J Studios moves toward a full commercial launch. For those looking to dive deeper into development, the studio is also centralising its community efforts on the official Reforj Discord.
Update: 20th Feb – the original article had a quote from Chris van der Kuyl. This has been removed by request.
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