It's definitely closer to the mythology. Hades may be the final boss but only because you're really not supposed to leave. Also since you play as his son there might be a whole "it's for your own good" thing going on, I'm short on funds so my knowledge is second hand at best.

Yeah, Hades in this one isn't some evil jerk. He's basically an over-worked administrator in charge of a processing a never-ending stream of the dead, while his rebellious son tries to escape to the living world. He's more tired dad sick of his son's antics than evil-doer.