What about SS2 turned people off so much? I played both, they both got extremely boring quick in single player, but were a blast in coop. What about SS2 was so much worse than SS1?
Correct. If someone says they didn't like Serious Sam the first thing you must ask is "Did you play co-op?" If their answer is no then by law you are allowed to 1. Punch them in gut 2. Ignore their opinion.
Serious Sam is the Diablo 2 of FPSes. It's a great LAN party game to play with friends while drinking heavily and eating really unhealthy snacks. Of course most gamers probably do the drinking heavily part without the friends already, but if you've moved out of your mom's basement maybe you too can find some friends.