Don't even bother if you already have Serious Sam FE/SE and/or Xbox Serious Sam.
Serious Sam Next Encounter is about abandoned mothership who released monster throughout time, and it's up to Sam 'Serious' Stone to fend off these uglies DOOM style. Mental apparently is taking a day off and told one of his servants to not use the timelock. But the servant didn't listen and jumps in anyway, thus starting the game.
Graphics: For a system that's more powerful than the PS2, the game's graphics are very bad, textures blurry whenever you walk up-close to an object, and animations are cruddy, especially when Sam's reloading the Double Barreled Shotgun. The graphics are just plain bad. The only good thing about the game's graphical engine is that the frame rate runs very smoothly.
Sound: Most of the Sounds in the SFX department are recycled sounds from the original Serious Sam games, but the new sounds are not good. From the new Uzi pistols cruddy gunfire sound effects to the very cheesy guitar riffs when things heat up during battle. And the new explosion sound effect is very disappointing as well. Sam's voiced by the same actor who played Sam in the original games. Some of his one-liners are funny, but the game's humor fails as much as it succeeds, or worse.
GamePlay: Because it's a Serious Sam game, you'd expect to fight literally hundreds of monsters at a time. It does. You walk into a room, and monsters appear out of nowhere assaulting you from all directions. But what this game can't do that the Original did is constancy; enemies appear all over the place without end with limited ammo, armor, and health in the original. In this one, though, after you kill about 30 or 50 enemies in one room, items appear in the center of room and the battle ends. But once you pick up the arrowed item, more enemies appear. The point I’m trying to make is that Next Encounter isn't as frantic as the original game, even when you crank the difficulty all the way up to Serious, because all it does is makes the enemies harder to kill and you easier to kill.
Tilt: only pick this up if you want a game that throws you a lot of monsters a once but you don't have an Xbox or your computer can't handle the FE/SE of Serious Sam. If you have either or both of those systems, stay far away from this game.