Open RPG Maker - Open RPG Maker is a free and open source clone of features from the RPG Maker series (i.e.
Godot Engine - Feature-packed 2D and 3D open source game engine.
RPG Playground - Make your own Role Playing Games, fast and easy.
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
RPG Paper Maker - Website
Unity - The multiplatform game creation tools for everyone.