I was a bit reluctant to try this game, since the thought of singing in front of other people was less than appealing. However, once I put on the headset and the music started, my whole attitude changed.
By singing in tune and along with the proper cadence, you score points that can be used to unlock new characters, songs, bonus videos, and character outfits. Each song has a "difficulty level", and believe me ... "Ladies Night" is a lot more difficult than "Kiss Me". This can be a bit frustrating for younger children. You can choose the difficulty level to help overcome this issue - it can "go easy" on you, but if you're too bad, you can actually be booed off stage. Funny when it happens to my wife -- but my 7-year-old doesn't find it too funny.
Make sure you understand which songs are on the disc, and that you like them. (Although even the songs you don't like tend to grow on you after you've belted them out a few times...) There's a good cross selection from the 70s, 80s, 90s and today, with a little over 30 songs total. Different styles are included as well, although most songs are ones that charted in the Top 40, and the selection is a bit skewed toward late 90s & early 2000s.
Despite a few minor shortcomings, this game is tight, and with 1-8 players, it's a great group or party game, and can be used by the whole family, or a group of friends.
One final note -- the headset that comes with the packaged set is a bit small. If adults plan to use the game, you probably want to buy the game by itself and spring for Sony's headset -- it's a bit bigger and seems to be a little more solid.