Rig and animate a couple of simple game characters

I am a programmer developing a small puzzle game in the game engine Unity, aimed for smartphones and such. To make the player more connected with the game, and to give some sort of meaning, I have added an avatar that follows the player from start to finish. That avatar travels to the different levels/cities, and meets other characters along the way. Along the path of the game I plan to have my avatar encounter life changing scenarios, like finding a dog, finding a partner, breaking up, finding a new partner, loosing a child, having new children, growing old. In the end of the game I plan to let the avatar die of old age, but with children and grand children by its side. The avatar and other world occupants are made of simple geometrical shapes, like cubes, cones, spheres and the like. There are no faces or humanoid details. I hope to be able to tell the story with animation and music/sound. The different scenes in the game are made up of about 100 unique animations/movements. Those movements are combined in different way in the timeline in Unity to make up the action in the scenes. In the animation design document included here there is more detailed instructions.