It really has nothing to do with the engine. The animation must be done by hand, and it's usually done out of the engine. And believe me, doing proper animations is hard as hell, requires lots of skills and it's very time consuming.If only this game was made in a different engine. The heavy polygons especially during the animations (the titties anyone? :/) is kinda offputting. Imagine this in the Unreal engine :O
A gamedev can do a game only as good as his skills and resources, the engine is kind of pointless here.