This looks like it'll be fun! Big question, though: will we be able to modify the doll assets? Retexture the models to our liking, or add stuff like clothes, hair, and new body shapes?
For example, I'm a big fan of Mortal Kombat, and while I like the catsuit look of your ninja girls well enough, I'd be in god-damn heaven if I could dress them up like the ninjas from MK 2 and 3.

Make the dolls customizable, and I'm sold!