A grand old arcade shooter. Co-op and all. Seriously
Here's the story so far: An evil guy named Mental has sent his legions of baddies to Earth throughout history in order to destroy humanity. You take the roll of the Sam "Serious" Stone. The beefy hero with enough weapons and one-liners to rival Duke Nukem. Sam is sent back in time to repel the invasion.
Serious Sam plays much like an arcade shooter. There are no complex puzzles or tricky collecting or escorting objectives. the only objective is to mow down everything and anything that moves. There are other things to do though, much like DOOM, there are many secrets to find around the huge maps. The secrets have specific completion criteria like destroying all the palm trees on the map or having a specific enemy destroy a wall. Finding all the secrets adds to a score meter.
Though there are no real innovations to the FPS formula, the developer Croteam managed to make things interesting, like the sphere, a secret spherical room allowing movement on every surface in the room. The weapons are also an interesting mix of familiar and new. There are the classics like the shotgun, single and double barrell, the dual revolvers, the rocket and grenade launcher. On the other hand there are the outlandish weapons like the plasma gun, the Cannon (picture a pirate ship cannon) and the serious bomb. The serious bomb is essentially the BFG9000, killing everything on screen(except you).
On the Xbox, there is no online play but there is system link and splitscreen. with deathmatch and other basic FPS modes. ther is a cooperative mode which fun if you have a friend to power through it with.
All in all. Serious Sam is fun by yourself or with a pal. whichever works.