One of the first mods for Serious Sam The Second Encounter, created by a veteran of the SeriousZone forum - Dances with Kleer (DWK). The project is based on changing the appearance of enemies, weapons and effects, as well as increasing the speed and height of the player's jump. As the author himself notes:
Once upon a time there was this guy
who kept hearing about this game
called Serious Sam. Curious, he
downloaded the Demo. Blown away by
how cool it was he had to have the game.
First he bought The First Encounter and
then he played, then played some more.
Then he had to have The Second Encounter.
Then he played, then he played some more, and some more....
Then finally he learned to Dance with the Kleer.
AND DANCE HE DOES!