The Serious Sam Collection has been rated by the ESRB for PS4 and Xbox One. The collection was originally released for the PS3 and Xbox 360, so the presumption is that it will feature the same games.
Those games were Serious Sam HD: The First Encounter, Serious Sam HD: The Second Encounter, Serious Sam 3: BFE (and the Jewel of the Nile DLC pack), and Serious Sam: Double D XXL. Back in 2013, it was improved with updated visuals, textures and character models.
The ESRB rating for the PS4 Serious Sam Collection states the following, but doesn’t confirm which games will definitely be featured.
This is a collection of first-person shooters in which players battle aliens and monsters in frenetic combat. Players use pistols, machine guns, shotguns, and sledgehammers to kill numerous creatures. Large blood-splatter effects occur during combat. Enemies are sometimes shown blowing themselves up into bursts of limbs and blood. Players are also able to rip the eyes out of creatures’ heads and/or rip the hearts out of soldier-like aliens. During the course of the game, harpy-like enemies are depicted topless (though usually from a distance). One character briefly references drugs in the dialogue (e.g., “I’m supposed to be doin’ blow off a stripper’s a*s right now.”). The words “f**k” and “sh*t” appear in dialogue.
The last game in the popular series was Serious Sam VR: The Last Hope. The virtual reality shooter appeared in 2007 for Oculus Rift and HTC Vive and took the form of a wave-based shooter.
A release date for the Serious Sam Collection for PS4 has yet to be announced or officially confirmed.
Source: Gematsu