Combos is like a DDR game where the user is supposed to perform the various actions on the top screen in a given amount of time. There are 4 different actions one can perform with the stylus and also the 4 buttons map to each action.
Thanks to cid2mizard for the news.
http://palib.info/forum/modules/newbb/viewtopic.php?viewmode=flat&type=&topic_id=4360&forum=38