Needless stylisation and dampened stealth reinvent the series making it different but not bad.
The single-player is very short and very easy. Fans of the previous titles will find the 'realistic' difficulty setting significantly easier than the 'normal' of previous games. On the hardest setting, skilled players and whiz through the story of a whistle stop tour of Sam Fisher's adventure to find who killed his daughter in 5-6 hours. What makes the game so easy are several things.
Firstly is the dampened need for stealth and lack of realism seen in previous games. Having removed 'detection = failure' principle, the tension and need to be stealthy simply isn't there. Gone is the tension and patience of waiting for the right time to attack in favour of fast paced shadow skulking, table hopping and guns blazing. Several of Fisher's keystone stealth techniques have been replaced with more 'actions'. For example, there is no longer a 'lethal' or 'non-lethal' choice when taking down an enemy. If it's a close up take-down, its more likely to be several brutal shots to the chest and head as opposed to a knife in the back. Sam has also lost the ability to move bodies once incapacitated. While bodies can be moved before they are dead (grabbing them and dragging them into the shadows before taking them out) it is lacking (especially as it is possible in Assassin's Creed II). Sam's abilities such as wall runs (where he can stand split-legged high above a hall way) or take out enemies by hanging upside-down on a pipe are gone. These have been replaced by all or nothing killing moves. Your only choices for take downs involve leaping from your cover and exposing yourself or dropping them from the shadows with your silenced weapon. Given that ammo is unlimited, the latter is most common and does away with the conservative approach to resources in previous games. Sam's gadgets have also significantly diminished from stealthy remote cameras and gas grenades to frag grenades and remote mines. They make it hard to do things quietly.
Another flaw is that the game simply feels too unrealistic. For a man of Sam's age, he moves around incredibly fast and monkey like up pipes and walls. The developers needlessly did away with night-vision goggles and made a the game fade into black and white when your character is hidden in darkness. Moving your character into the light means you are visible. Black and white means your invisible. There are two problems with this. Firstly, this means stealth orientated players will play most of the game in black and white. It is as though the engine wasn't sharp enough to render brilliant graphics and colour, so they developers tried to hide it in needless stylisation. The second problem is that while you are in the shadows - you can still see everything as clearly as normal (with no goggles). Enemies in the shadows are blind as bats (with no goggles or ears). This means that while in black and white, you can walk right up to an enemie's face and they won't even see you. You can also run freely around them without them even noticing. Its really quite poor for a game striving realism.
All things considered, splinter-cell isn't a splintercell. Fan's of the originals will be disapointed and (like me) only play out of loyalty. It must be noted that the developers were seeking a new audience, and in that respect, they succeeded. While it is sad how they compromised so much that made the series great, SC;C is a great stealth-action game for those new to the genre. It is easy, fast and much packed with combat. While the levels are short and linear, they are enjoyable (some levels are terrible). The story is also original, driving and well supported enough to maintain engagement.
The other half of SC;C is in the co-op, 'Deniable Ops' mode. This carries all the same features previously mentioned into a coop story that is equally as long and action packed. The joy of this is doing it with a friend with whom you can cooperate. While this makes the game much easier, it also makes it more fun. Carrying over single-player flaws and greatness, the coop story and 'arena' missions are pretty much more of the same. While there is no real competitive multiplayer, cooperative efforts are encouraged and rewarding. Rewarding in the sense of new outfits and weapons for your character. There are several game modes to play in coop as well leaving plenty of room for new players to learn the ropes before heading onto greater things
Overall SC:C is detached from the series as a completely different game with the same title. Stealth is all but gone and the game rewards you for action more than sneaking (even making it difficult to lure a guard into the shadows without blowing something up or shooting a bullet past his ear). Sneaking for the most part is essentially pointless and only give you an advantage to action sequences (flanking etc). It doesn't really help doing it separately. The singleplayer is driven by a good story that comes to a quick end making for a short and sweet experience. Doubled by coop modes, the game has slightly longer re-play life.
All things considered, the game is short, sweet, easy. Discouraging for stealth fans, but good for those seeking something different.