Mafia II features a lot of nudes. 51 of them to be exact. I know this because the game features 50 collectible Playboy centerfolds that can be viewed (after collection in game) in the main menu. There is also one nude in the in game sequences themselves.
The inclusion of 1950s Playmates apparently is intended to add an air of authenticity to the period in which the game takes place and to the seaminess of the mob lifestyle of the game’s protagonist. While the Playmates presence in the game are actually anachronistic if the game were set in a historical United States (since the game’s main action takes place in 1943 and 1951, years prior to the release of Hefner’s magazine in actual history), assumedly the fictional city of Empire Bay resides in an equally fictional alternate timeline of United States history, in which Playboy emerged on the American scene about a decade early. The authenticity of these nudes is probably derived more from their more demure quality (something that most players would associate with pornography of a period perceived to be more prudish than the current one) than an adherence to real historicity.
In that regard, the nudes featured here are certainly more buttoned up than what one might expect to encounter when performing a Google image search with SafeSearch disabled in 2010. None of these images feature full frontal nudity (as no Playboy pictorial did prior to the 1970s). Many of them feature women merely in sheer clothing or often feature a bare bottom rather than bare breasts and are generally less raunchy than contemporary pornography. Nevertheless, the game makes it abundantly clear that these nudes are here to be viewed.