I like it 10 x better then Serious Sam. Obviously it's repetitive and has almost no story, that's the point of it. :p Pointless slaughter and killing of awesome looking demons is sexy as hell levels! It has to be one of my favorite games of all times. Even though you can easily beat the game in under 4 hours, it's worth every penny. The replay value..Oh the value! Killing for hours and hours at a time. The Hell level is also awesome, even though Lucifer is a pushover.
The expansion on the other hand I don't like. The levels are pretty nice, but they are too simple and the enemies take too many shots to kill. The other thing is, the expansion runs like garbage on almost any computer. I have a Radeon 9600XT, 1GB Ram, and a AMD 3000+. Painkiller ran around 80FPS, the expansion...20FPS. Painkiller was fun because it was hundreds of enemies coming at you at once and with one or two shots they would explode! In the expansion it's less enemies, but it takes a lot more damage to kill them. That isn't fun, it's annoying! Also they removed the awesome rock soundtrack and gave it this like....real soundtrack. It just doesn't fit in at all. The last thing is, the cutscenes look EVEN WORSE then in Painkiller (hard to believe I know)
Think while it's still legal.