You may have to download grifball from the file browser. Press start, down, and go all the way to the right. As for team games, as long as it supports team, to the right of Map Variant on the custom game screen, click on game options, go down to teams, and put it on "enabled".
I made a new word, "foxephant." It's for those people who are crazy, but they never forget.- Me XBL GT: LAG Donut Jenny