You need to space and + just before you add the command line tweak to make it work properly.
Note. 1 enables the given setting, and 0 disables it. X stands for the level of settings with 1 being lowest and 3 being highest.
Where to Find Crysis 2 Config File
Go to X:\Electronic Arts\Crytek\Crysis 2 folder
Find and Open in Notepad file system.cfg
Crysis 2 Tweak Guide
Changes Game Effects such as body-related stuff like when they disappear.
Changes the quality of the detail of the objects.
Changes the quality of the particles.
Changes how you interact with the world, higher setting will consume more of your CPU’s power.
Changes the quality and amount of post processing used.
Changes the quality of the Shaders.
Changes the quality of the shadows.
Changes the quality of the sound.
Changes the quality of textures.
Changes the quality of the water.
Note. Command Line Tweaks with + before them are meant to be applied using target box method by adding these tweaks into shortcut properties so to launch the game with these options. If you were to add these tweaks in Crysis 2 System CFG or via console, you won’t need to add + sign before them.