As much as I love Devil May Cry, the art and dialouge just can't carry a plot though very well here.
The art, while well done, doesn't convey a good picture of what's going on half the time. There are lots of appropriately creepy scenes with skulls, swirling darkness, and such except that they just end up being confusing to the action. Are the skulls attacking? What just happened? And now everything's dark for no reason...
Dialouge is sporadic and while Dante stays in character well, there isn't much help explaining a plot. Even if you're famaliar with DMC3, it can be hard to figure out what's going on. More dialouge, or even inner monolouges would help to make sense out of a lot of the scenes.