Open-source friendly game studio Wolfire Games has released their Overgrowth title, which was released back in 2017 and the sequel to the Lugaru game, as open-source software.
Overgrowth being open-sourced follows Lugaru being open-sourced a decade prior. Overgrowth has been running on Linux for a decade along with macOS and Windows. While the action video game was just formally released in 2017, it had been in development since 2008 and saw frequent alpha releases and Steam Early Access support.
Wolfire Games has released the game’s code as open-source while all the art/assets are not. But Wolfire has dropped the price of the game from $29.99 USD to $19.99. The game’s code is released under the Apache 2.0 license.
Those interested in learning more about the Overgrowth open-source release can do so via Wolfire.com. The code is up on GitHub.