The first serious sam (first encoutner&second encounter) wasn't really cartoony (at least,the xbox version).It only used more colors than other games and the enemy design was unusual.Susan Arendt said:Well, guess this means I won't be playing Serious Sam 3. No disrespect at all to the developers, but the ridiculous over-the-top cartooniness was what set Serious Sam apart for me and made it something special.
Only the 2nd game was cartoony, and the game was simply bad.
So returning to the roots might be a good idea.
Btw,have you played warsow?
edit: ninja'd