In Call of Duty 2, the PPS42 is infrequently found in the Soviet campaign. It is a submachine gun that accepts 35-round magazines. While it doesn't have the magazine capacity that the PPSh-41 has, it makes up for it with very controllable recoil. In fact, its recoil is almost exactly the same as the PPSh-41 in Call of Duty. This means that the PPS42 is very controllable and can be used at short or medium range with ease. Its lower rate of fire makes it easier to control as well, but this might be a disadvantage in close quarters.
The PPS-42 was originally slated to be in Call of Duty: World at War, but was dropped before the game was shipped. It's likely that it was replaced by the PPSh-41. Unlike the other cut weapons, it lacks a HUD icon, which suggests that it was dropped in an early stage of development. The only things remained are Create-a-Class image and animations. Posters of it can be seen in the multiplayer map Revolution.
The PPS-42's weapon selection menu icon for World at War