Admittedly, I suck at these kinds of games. However, the constant sliding of the character, weird control schemes, awkward wall mechanics and a lack of a "tutorial" level kinda hinders it. Keep in mind, "tutorial level" means a level that is quick, simple and covers everything, without holding you back.
Now, this game is rather interesting. Sucking blood to restore health, or choosing to kill enemies is a rather cool mechanic. The stealth mechanic is interesting and provides depth, but is a little too easy, or complete bull when the enemies can fire through walls. Perhaps more enemy depth? Chain is kinda cool, but only really needed here and there. Hooking enemies was cool, and perhaps making it to where you can hook through certain floors for an option would be nice.
Overall, amazing concept, but still lacking in execution.