PE2 is chocked full of all sorts of goodies to find as you search for NMC's. Real time battles. The battle engine has also been revamped. No more standing still, you must keep moving if you want to survive. It has a decent story and great cinematics.
Control is a little awkward at first while in battle, but can be worked with.
As far as sequels go PE2 should have been a prequel. It's a good game, but the original had a deeper story and more varied locations. The battle system I could take it or leave it. Overall I would say that PE2 is a winner, but it's no Parasite Eve.