Serious Sam: The Second Encounter Demo
After the release of Serious Sam, the Croteam started developing the successor 'Serious Sam: The Second Encounter'. Today the official demo of the successor has been published and is 110MB.
The official demo is:
Sam is back in the all new Second Episode of his battles with his arch-enemy Mental! This demo contains one playable SP/Cooperative map, a technology level and one Multiplayer deathmatch level.
If you are not put off by the 110MB, you will find links for the download on the Croteam page.