To play bump:
When it says PUSH! click any button. You should see the little bar filling up and emptying. Press another any button to stop it. You want to get the bar as full as possible. Your tama should then bump (hence the name of the game) another tama. The one who is still standing at the end wins.
Tips:
Don't be really heavy, but try to be a couple pounds over the normal weight. (How much you weigh also affects your score)