CodeKeep - Codekeep lets you store and share bits of code and text with other users. Snippets can be organized into folders/labels for instant reuse.
Godot Engine - Feature-packed 2D and 3D open source game engine.
thiscodeWorks - Save and share code that works
Unity - The multiplatform game creation tools for everyone.
Refactor.io - Share your code instantly for refactoring and code review
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.