shapez.io

shapez.io is a free, open source factory-automation puzzle game that strips the genre down to its abstract core: instead of mining ore and crafting machines, the player extracts colored and patterned shapes, then uses belts, cutters, rotators, and stackers to cut, rotate, color, and combine them into more complex shapes. The map is infinite, there is no combat or survival pressure, and levels unlock purely by delivering a target shape through your production chain.

The game is self-described by its developers (tobspr Games) as "an open source base building game on Steam inspired by factorio!" and it shares Factorio’s conveyor-and-extractor core loop in a more relaxed, pure-puzzle wrapper. The original is browser-based and free, and the same engine was used to ship a paid Steam release; only the original open source release under GPL-3.0 is the fully free version.

shapez.io supports single-player and online multiplayer, runs in any modern browser and on Steam (Windows, macOS, Linux), and ships with a built-in level editor. It is the most direct open source answer to Factorio in the factory-automation genre and one of the few open source projects that explicitly targets that audience.