Unity - The multiplatform game creation tools for everyone.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Godot Engine - Feature-packed 2D and 3D open source game engine.
SketchUp - 3D for Everyone
AC3D - AC3D is a 3D software for games, virtual reality and flight simulation, scientific, medical and general data visualisation, rapid prototypes of 3D designs, 3D printing, Google Earth, X-Plane, Second Life and more.
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.