The Number One Hits Expansion Disc Add-on for Lips has 9 achievements worth 250 gamerscore.
Hit all Timed Noisemakers in 1 song
Trigger all Timed Gestures in 1 song
Get 50 Combos
Get 200 Combos
Earn a Bronze Cup or better on 1 song
Earn a Bronze Cup or better on 20 songs
Sing 20 songs in Duet mode
Gain 150,000 total stars
Earn 1,000 total medals