Not what I expected, in a good and a bad way
I didn't like the way the game was built. Mixing too much of different things form other popular games shouldn't have been the norm on this title. Castlevania has too much history of 2D platforming and a bad run on 3D games for me to expect it to be as good as the previous titles of fame. Adding Kojima to the mix was supposed to make it even better, but playing through gimmick-laden levels and making it very piece-wise was not a good idea. Some levels took the fun out of exploration due to bad level design, making it hard to find items or even the way forward! The jumping mechanics were not very good for the type of platforming that requires precise timing on several levels. The God of War-style QTEs were not that good, more of a nuisance than anything else, really. Having two titan battles and a dragon brought out the Shadow of the Colossus-type battles, which were good, but too few and far between to matter. Backtracking was tacked on instead of thought out to open levels. Why didn't they use the split-level path like on Castlevania 3? That would have made going through the levels better and added replay value. And the variety of level length/difficulty was atrocious: one level would be a boss battle or a short 10 minute trip through a level, and all of a sudden you'd be facing a multitasking, fighting, and puzzle level for half an hour or more. The chupacabras challenges to gather your items back were awful.
I initially thought of giving this game a 6/10, but what I didn't expect was that the story, completely new and revamped, would make me end up liking the game enough to give it a 7.5. I really liked the story's progression and how the characters were played out. The ending was incredible and convinced me to buy a sequel if it's developed. I'm definitely biased, as I have played almost every Castlevania title since the series started on the NES, but overall, this was an OK game. Not good enough to replay, even with its challenges and difficulty levels (if you're into that), but worth playing once to experience the story.