It has flaws, but it's a good experience for the price. Like the other poster said, don't go in expecting Modern Warfare 2 and you'll come out with a better opinion of the game.
$20 is not a bad price for GTAIV, but it's kind of shitty that the 360 version was $9 yesterday, which was a good deal. In either case, I was hoping for a GTAIV episodes deal.
You're probably right about it being Liverty City Stories. Fits the clue.
Man, I was kind of hoping for a deal on the GTAIV DLC.
EDIT: wait, nm. I misremembered the clue.