Just beat single player with team listed in topic to try and get the Avengers Assemble achievement, and didnt get it. I'm pretty sure that those three were all members of the Avengers. Is there an achievement bug, or am I wrong?

Some people over at x360a are reporting bugs with those achievements.

I did use 1 continue, but I wish they would clarify that in the description

Try it again without continuing, but some people are still saying it's bugged so, good luck.

Do you know if difficulty matters, cause going on easy instead of normal would help...not to great at MvC2

No idea unfortunately. All I know is I went through with an X-Men team on easy without using continues, and did not get it. But i'm not 100% sure 3x Cable counts as X-Men.

LOL way to take Jeff's advice from the one year anniversary video...I'll wait a few days to try again and see if this is a widespread issue or if parameters have been hidden

I have all the team achievements it didnt give it to me when I used capt. america, hulk, and iron man. But It did give it to me when I used capt. america, iron man, and war machine.

They work, you just can't use a continue. You can do this on any difficulty though. A cheap and easy way I found to do it however was to use Iron Man, War Machine, and Captain America. I would just pick Iron Man first and War Machine second. Just spam their Uni-Beam/Shoulder-Beam move till you get a level 2 hyper meter then use their hypers together. Just rinse and repeat for all the stages including Abyss and it is an easy win

man no continues abyss please be kind to me.

cant wait for an avengers film.