Alternatives to GDevelop

2D and 3D game engine

C# scripting capable version of Godot game engine

Real-time strategy game engine for Westwood games

Lua-based game engine

Game engine for development of desktop, mobile and web games

Open-source engine for Heroes of Might & Magic III

Complete development tool for making 2D games

First person shooter engine

Open-source continuation of Bungie's Marathon 2 game engine

Build engine port backed by GZDoom tech

Engine for iD software's Quake

Enhanced source port of Doom, Heretic, and Hexen