If you need a game to fully enjoy and that needs a replay value, don't buy this game, still, the game is great.
The game has 3 new characters, Lili, a female character who is envolved in the King of the Iron Fist Tournament because of his father, Dragunov, a Russian army general, and Armor King, well he isn't really a new character but he wasn't in Tekken 5 so we could say that he is a new character too. In total, there are about 35 characters, they have their own style of fighting and combos. The game is same as before, especially Tekken 5. It has same prologues and epilogues and stories.
There is a new mode called Tekken Dojo, which you can train yourself by fighting with different levels of characters(for example you can fight with a Beginner or either with a Tekken Lord). This mode is really addicting, but it's too repetitive because all you can do is fight and some challenges. Well one of the addicting, but still repetitive was the customization of your character. Once you get addicted by this, you'll fight just to earn money, not to be the 'Tekken Lord'.
The game is simple, all you do is fight, there are a lot of combos, but it's very difficult to master all the combos. So I recommend you not to buy if you aren't ready for the combos. The game is simple, but as you defeat more enemies, the enemies will become more stronger, Stronger means that they defend nearly all your commands. In the end, the gameplay has nothing new to offer, it's same as before, there is practice mode, arcade mode, survival, etcetera, which was able to play in previous Tekken series. The unique new mode was(and something big) Tekken Dojo.
Graphics were just terrific, no doubt about it, it has the best graphics on PSP until now. Every character is perfectly designed, and they speak their own language(well not really, because Christie, who is a brazilian, speaks english but there are a lot of languages spoken). Well, language is not important, but it was still dissapointing hearing english from brazilians, or any other americans or europeans.
But honestly, who cares about languages? Besides the voice acting is surprisngly good. The sound is great, as the other Tekken series do, it
has hit effect, voice acting, stage music, etcetera. But the important part is the gameplay, don't you think? The sound has not a big value for the game. But yes, the sound is good.
And still does who think that this game will last at least 1 month, you're wrong. The game is too repetitive that you get bored easily unless you like other Tekken series or this type of game. So as an experienced person, I recommend you not to buy this game unless you're extremely good with this game, or like Tekken, or other fighting games. My Tekken : DR lasted 2 weeks, really.