itch.io

Includes or is about animals

Provides tools that let you customize characters with either free form sliders or combinations of pre-made options.

Godot Engine - The free and open source 2D and 3D game engine

Unity is a game engine for 2D, 3D, AR and more

Voxels are small geometric primitives used to construct larger worlds. Sometimes called 3D Pixels, they are typically cubes.