EASY TRICK TO GET LOTS OF RARE ITEMS - Make a custom stage like this one. Then, do a stock smash with a lvl 1 CPU. Turn off all items except master balls and containers. Select your stage and begin the match. Launch your CPU into one of the cannons so it'll be trapped launching back and forth and can't bug you. Keep throwing balls until Mew appears and he'll give you a rare item. You're welcome.