Just picked up Merc 2 at Walmart and it does not hav 2 player offline co op whats with that?  Not sure if I want to keep it now.  Before you asked wife picked it up for me so I couldnt check the back at time of purchase.  What do you think keep it or return it?

Why would you take it back because it lacks that one feature?
If you liked the previews or even liked the original Mercenaries on the original Xbox and PS2 then keep it. I would play it and keep it just for the simple fact, you unlock achievement points and that its a awesome game.

If you haven't did the above and don't agree with the above then take it back.
And as I might add, did you crack the game open, like the plastic casing, if so you can't take it back to get your money back, you can only exchange, I think...

Keep it, you can still play online co-op

If you liked mercs one you ought to have at least some fun with this one. I say keep it.

I bought it for the co op so me and my son could play offline. I did not play the first one but heard it was good. I did not pop the plastic off..