Castle Game Engine - An open-source 3D/2D game engine for ObjectPascal.
Tynker - Game Worlds for Kids to Learn Programming
Open 3D Engine - Open 3D Engine is an open-source 3D game development engine in real-time.
CodaKid - CodaKid is an online kid’s coding academy offering coding courses for kids, Minecraft modding, Robox coding, and video game programming courses.
WaveEngine - The definitive free cross-platform mobile engine to unleash your games using C#.
CodeCombat - Learn programming with a multiplayer live coding strategy game.