P.T. Barnum was right.
However, the corollary to his famous statement is that there is also a schemer born every minute to take advantage of those suckers.
Perhaps a more apropos saying for the App Store is that the crappier the developer, the more likely he or she is to hype his applications out of all proportion and by any means necessary.
Personally, I have a simple rule: The more a developer hypes their own game and slathers on the superlatives, the less likely I will be to buy it. Let the app speak for itself, and allow me the opportunity to make decide whether the game is worthy of superlatives, and I may just do it.