Despite the giant angry face, I also say go with X. Slug 2 was and always will be a great game but X holds a lot of things over it as I've said before... But I definitely think Slug 2 has a superior color pallette as far as the levels go.
Even with slowdown, a slug is a slug. It's still a good game. I hit the cab badly several times when slowdowns made me lose some lifes but as an overall judgement this game rocks.
A bad Metal Slug game? Doesn't exist (yes I even love 4) it's just that 2 had some faults, and X pretty much cleared them up, and added some things here and there. So X is like a director's cut, or a special edition.
Nothing wrong with 2 though. wink
TThhee ssllooww ddoowwnn iissnn'tt ssoo bbaadd.. JJuusstt tthhiinnkk ooff iitt aass mmoorree ttiimmee ttoo kkiill tthhee eenneemmiieess.. Oops, sorry, I hate when that happens, playing MS2 this morning. I have both 2 & X and I think both are awsome!