UltraStar Deluxe is a clone of UltraStar and its main news are the interface, updated and more elegant and new and attractive game modes.
Play with up to six singers in UltraStar Deluxe, although you'll need a microphone for everyone.
Party game mode is the same you can play in SingStar. Your goal is to win throughout the different tests and games purposed by the game: duel, blind sing, up to 5000, etc. Ultrastar Deluxe is more than a karaoke, give it a try, it's free.