First-person shooter video game developed by Croteam and published by Devolver Digital. The game is a port of Serious Sam 1 to the Xbox. Gameplay-wise, Serious Sam: Xbox is essentially the same as both Serious Sam: The First Encounter and Serious Sam: The Second Encounter, though there have been many changes and modifications. There are also several features which are otherwise not present in Serious Sam 1. For instance, there is a "multikill" system, which multiplies your score if you kill...