if you pirate them they're all worth playing. 2 was a lot of fun with a friend, but mainly just because the literal final cutscene is so fucking stupid and hilarious my friend and i still occasionally text each other about it and laugh. 3 was pretty bad but shooting people in the head from really far away never really loses its luster if that's your thing, and the same can be said for 4. i cannot stress enough that you shouldn't pay for these games though, they're literally just the same fucking thing copypasted over and over from beginning to end and the only things they add are more enemies and new rifles