It's a great FREE Tekken game, and a pretty good one.
There are two modes for playing online, but what you have to know is you can only play a limited amount of times each day, or your "free credit" of the day, and if you play good you also get extra premium chips that you can use to play more matches. What you can also do, and probably the point of the game, is to buy more credits from the PS store, so you can play more rounds if you feel like spending some cash to fix your Tekken compulsion. It's pretty smart to offer a game for free if they use this model because you don't have to purchase more credits since every day you log in you automatically win some credits for playing the game.
What I have to mention is that it's fairly easy to get 100% Trophy galore. Combined with the fact that you can upgrade your favorite player's stats and have a few modes to play, Tekken Revolution is a solid FREE choice for any PS3 owner. Thanks Namco.