After seeing this other post here and lot of talk about it, I thought it’d be a good idea to make a list of free or FOSS engines for people that were considering using Unity but probably won’t anymore, or that want to ditch it ASAP.

Feel free to add your own suggestions in this thread!

Engines:

  • Godot - Probably the “biggest around”, offers programming in both GDScript (very similar to Python) and C# with their Mono executable. Also has bindings for other languages thanks to their GDExtension API, such as Rust, Go and Nim. Has lots of material for learning and a community over programming.dev
  • Solarus - FOSS, for making SNES/GBA Zelda-like games (top down action rpgs). Programming done with Lua
  • GDevelop - FOSS, Similar to Construct2/3, focuses on visual scripting to define the workings of your game.
  • OHRRPGCE OHR - Putting this one here because I’m simply too amused to leave it out. Could work as an alternative to RPG Maker, if you happen to know FreeBASIC and don’t mind the really old school look of everything.
  • Stride - Probably one of the best options for high performance 3D games with C# programming. MIT license
  • Fyrox - Rust based engine. Allows both 2D and 3D development. MIT license
  • Bevy - Similar to Fyrox above, it’s made with Rust and allows both 2D and 3D. MIT or Apache license

Game specific engines - These are engines made to play a specific game, but they have enough tooling to allow you to make almost any other game with them

  • OpenMW - Should probably be a good option for anyone with experience modding TES games. There is a “new game template” on their docs
  • GZDoom - It’s Doom. If you really, absolutely, definitely, must have your game run EVERYWHERE, this is one of the best choices. You aren’t stuck to raycast first-person shooters, either, someone made a Donkey Kong Country with Doom and there’s also Sonic Robo Blast 2 Kart.
  • Quake 2/3 source ports - Similar to GZDoom above, but for those that need good 3D performance. A good option is YamagiQ2
    • Pretty much any implementation or sourceport of id games fits the bill. The most recent open sourced engine of theirs was tech 4, which ran Doom 3 and Quake 4.

Frameworks - This is for the programmers.

  • LOVE2D - Lua framework for making 2D games. Can also run on Android if the person installs the LOVE2D app
  • MonoGame - Formerly XNA, it should be the go-to option for people with experience in C#. One of its most notable games is Stardew Valley
  • libGDX - For people who want to make a game running in Java. Porting it to several platforms should be easy thanks to the JVM. Two notable games are Mindustry and Unciv (Civ5 clone)