Cinema 4D is an amazing program, but not a one-stop source for animation needs, especially if you're planning on making a 3D video game, for which you'll need Unity 3D. This three-part video covers the process of rigging a character in Cinema 4D and transferring to Unity 3D.
The first video focuses on rigging the animated character using joints. Unity 3D cannot read joints, so you'll need to convert them into traditional bones. The second video covers using the weigh tool to clean up the auto-weighting of the mesh to bones. Lastly, the third shows you how to add an animated walk cycle to your character, then convert from CD4 to FBX for use in Unity 3D.