Ready Player Me is described as 'cross-game avatar platform for the metaverse. It lets you create a 3D avatar with a selfie and use it in 300+ compatible apps and games'. There are six games similar to Ready Player Me for a variety of platforms, including Windows, Mac, Online / Web-based, Android and iPhone. The best alternative is MakeHuman, which is both free and Open Source. Other Ready Player Me like games are VRoid Studio (Free), DAZ 3D (Freemium), Character Creator 3 (Paid) and Mixamo (Freemium).
MakeHuman is an interactive modelling tool for creating realistic 3D human characters. These models can be exported to several computer graphics and animation platforms including Blender, Unity 3D, Unreal Engine, OpenSim and Second Life.
pixiv has released "VRoid Studio", a character maker that allows users to create, in easy steps, 3D model characters which can be used in various VR\AR platforms as well as the production 3DCG animation and games.
Creator 3 is a full character creation solution for designers to easily create, import and customize stylized or realistic looking character assets for use with iClone, Maya, Blender, Unreal Engine 4, Unity or any other 3D tools.