It's fun to play. You'll need a microphone but it's worth picking one.
There's an offline mode and an online mode.
If you pick the offline mode you'll be able to pick one of the 33 available songs. Most of them are old ones, and a few of them are fresh new.
You'll be able to choose a background for your song: your avatar (in which you can customize, buying clothes/accessories) or a random video.
To use the online mode, you'll need to buy an 'online ticket'. They cost:
5 dollars - 1 day;
10 dollars - 3 days
30 dollars - 30 days.
I've bought the 3 days ticket.
The gaming advertise says there are more than a thousand songs in this mode, but I did not see the whole list, because they did not display the whole list. They do display the "100 most popular songs" and there's an option to search for an artist or a song, but I would prefer if they had displayed the total amount of songs instead of asking us to search for an artist/song.
Anyway, it's worth buying this ticket because you'll be able to sing many other cool songs (from Little Richard to Iron Maiden).
3 days were enough for me to use it.
30 days would be too much, but it's up to you.
There are also some (not fun) mini games in the game.
All in all, I'd recommend it. Despite the bad graphics, t's fun to play.