I didn't play the game or read the manga before I watched it and at first I hated it a lot. And at some point I even just watched it for Shiki. But I wouldn't say this anime is confusing or a waste of time. I loved the anime and actually wished it would have gone on a little longer. The ending was kinda confusing but I thought it was great because it touches on the main guys feelings and makes him realize the things he has in life are important to him, like his friend. But it was to late when he realized that.And there were some confusing points like his blood quality's. But I seen worse anime than this and I enjoyed it.