Pocket MuuMuu (1999) was a Japan exclusive PSOne game that contained several downloadable PocketStation titles.
One of these unlockable PocketStation game is called COPY DANCE which is Simon Says meets DDR. It is all fun and games until you hit Stage 5 or 6, where you need to memorize an impossible combo to music.
Here is a quick 60-second review of this game you never played.
