MvsC2...unlocking things.

Can anyone tell me how you access the unnlockable characters in this game.... I got all the ones it would give me.... then I couldnt get anymore.... so. i went online and looked for ways to unlock the rest.... there are like 20 diifferent stories out there about how to do it.... and none seem to work. I played the "score challenge" mode (or whatever its called) and that seemed to work....because the Sentinal and Thanos became available... so I bought thanos.... and went to get more points to get the rest.... then when I came back they were gone again.... so. I dont know what to do. I have never even seen Gambit or Magneto available. any help? please?
thanks.

just keep beating the game over and over and over... you have to buy the pictures of guys though... like when you buy the characters then you cant anymore and only pictures remain... buy them and another series of characters will pop up to buy... it takes a while to beat the game so many times and get everything in the game... good training though... but computer isnt hard enough :cry: