An artful and atmospheric beauty.
First, I was blown away by the graphics and how the scenery helped set the tone. It is the best looking game I have ever played. You can control the character, but not the camera. At first I didn't like this, yet you'll quickly find yourself getting used to this style (a la God of War).
The idea is that the game tells a story and you unlock/buy new moves to dispose of foes as you look for the man himself. However, the problem is there are so many moves/attacks to unlock and you really only need a few to make it through the game. So, I found myself not really caring about unlocking/buying new attacks and more focused on content/gameplay.
The gamplay is great and handles itself very well (tight controls). Also, I've never really noticed a soundtrack until Castlevania: LoS. The game sounds amazing and really adds to the atmosphere; truly and epic experience. Paring great audio with a graphically enhanced game makes this a must play for the year.
Puzzles can be tricky at times, yet the game if fairly linear and easy to navigate... however, you don't mind it as it is a generous campaign with plenty to look at. Although, the story suffers greatly toward the second half (nearing the unbelievable realm), the overall package is an incredible experience. Must play of 2010.