Pain is a very... incomplete game, Pain seems like its missing alotta things, almost immedaitly after booting up the game it seems like the developers purposly left thinds out ranging from everything from, characters too entire levels, obviously with the intention of releasing more stuff for DLC making this games initial price point (9.99) a little steep. And with all the incoming DLC in the form of unlockable characters, new locations, and modes this game could prove to become very expensive.
Though Pain is initally lacking in overall content like i said, the game has some surprising depth and addictive gameplay. It starts off simple enough you launch a dude across the map hitting as many things in sequence to build up a chain, and causing as much destruction as possible. Though as you play more the game starts opening up modes (including spank the monkey which unfortunatly or fortunatly isnt what it sounds like) and introduces new rules and objectves. All in all you will quickly become addicted to finding all the horrible ways to hurt your poor (crotch quenching) character, and trying to find all the secret passages way to fling your flinging character.
FINAL VERDICT: Pain is pretty pricey at 9.99 especially with so many things delibritly left out only for you to later have to buy to extend the life of the game, but the addictive nature and graphically pleasing but not astounding technial aspects are a plus. So if you dont mind spending the $10 on a fairly incomplete package then go fling your character into as many mokeys as you can find.