Trying to steal Vray's thunder.
I'm gonna wait for Steam version
Programming animation in CryEngine is not an easy challenge. Here is a nice guide that might help you. Andrei Ghenoiu shared a video tutorial on some of the C++ programming aspects of animations and collisions.
First, start by creating a custom character using Adobe Fuse and exporting it to Mixamo. Select a few animations and export them as FBX. Work in Blender and import the result into CryEngine, and follow a similar process to import animations. Once character and animations are imported, change the character in code, and assign the proper animation using the Mannequin.
The second stream is about changing animations. The developer will guide you through some challenges along the way and show you how to create new crouching animations, and update the player collision proxy to reflect the crouching position, and be able to go under things. He used the Mannequin editor so that the tags can be properly targeted from the code.