Not reviews as such, but the British Board of Film Classification reports written when deciding age classification are oddly insightful:  
 

GTA IV: Episodes from Liberty City

 There are blood spurts as people are shot and stabbed etc. and pools of blood form on the ground. However, there is never any discernible injury detail and it is not possible to inflict post-mortem injuries, although there is considerable ragdolling as dead bodies are shot. The characters controlled by the player are able to attack and kill any other character in the game, including innocent bystanders.

The game includes some sex scenes. The sex is quite strong, but always masked and the characters concerned are invariably fully clothed (no nudity). In cut scenes the Luis Lopez character is seen to be on the receiving end of oral sex (slumped on a chair with a woman's head buried in his lap). The same character engages in sexual intercourse on at least two different occasions. For example he stands between a woman's raised legs and thrusts into her and he also bends a woman over a desk and thrusts into her from the rear. The game also contains strong verbal sex references throughout and there is one scene of full frontal male nudity (without a sexual context). 

Bayonetta

In BAYONETTA, the bloody violence is frequent and consists of clouds of blood, arterial spurts and flying limbs during combat, as well as 'torture' moves in which Bayonetta puts her enemies on a rack, into a spiked cabinet and so on. Such sequences are not presented in a realistic manner - one involves pulling a female monster to a rack and tightening a chain - with resulting breast jiggling - before the victim explodes in a puff of blood and body parts. Throughout the game, Bayonetta's enemies are fantastical rather than realistic in appearance, and the levels are mostly set within a clearly unrealistic universe. There is no opportunity to further damage bodies post-mortem, and none of the corpses stay in the environment for more than a few seconds.

The game also contains some moderate sex references, with numerous camera angles focusing on the female characters' bodies and costumes throughout.

WWE Smackdown v Raw 2009

The fighting features punches, kicks and various wrestling moves, with some matches involving the use of weapons such as chairs, ladders, dustbins, sticks, clubs wrapped in barbed wire and sledgehammers. The blows delivered with these weapons do not have a realistic impact and their use in any single encounter cannot be sustained for an unduly long period of time. The bloody injury resulting from any fighting action is equally unrealistic and it is not possible for fights to turn into ‘bloodbaths’.

More extreme types of matches see, for example, a defeated fighter being pushed into flames that surround the ring. The flames on his body are quickly extinguished and there is no detail of burn injuries. The theatrical presentation of such a fight is quite characteristic of the ‘pantomime’ nature of WWF and WWE wrestling, which is seen elsewhere in the game as, backstage, fighters play out various grudges and conspiracies as part of their storylines. This lends the work an element of fantasy which plays a part in removing the violence on display from a real-world setting.