Dark Souls 2 was always going to have the problem of being compared to its predecessor however I feel the story in the two games immediately changes the mood (i'll leave that for you to discover). The game is still challenging but in a different way, for example enemies disappear after being killed enough times which appears to make things easier but good luck farming souls when all the enemies are gone.
What I would suggest to really get the most out of your game is to view Dark Souls 2 as a separate entity to the first one, then you'll get the thrill of exploring a new place as opposed to just playing spot the difference.