ok here's how it works you need 2xbox live accounts (preferably gold)silver works 2. you will need 2 controlers now here's how it works with the 2 golds host a game of castle crashers with 1friend in it. ok when your count down gets to 2 on the starting screen(NOTE not on the charcter screen you pick before it) back out with ur main account an ur alt account will stay in start game an the exit. when u get back on with ur main account u will have unlocked all the characters an they will all be lvl256.
with a silver account if u want a lvl 256 find a player that has 1 an then do the same thing but basucally u will copy all his stats/character lvls/money/weps/animals/etc 2 ur account.
i hope this helps some1