Tekken 4 was the first Tekken game I've ever played. I bought it at a pawn shop when I was in 6th grade. Now that I've played all of the other Tekken games, I don't play 4 as much as I used to. But I still think it's a great game.
The story isn't really much. All there is to know is that every character has entered the KOIF4 and for their own reasons. As for why, Arcade mode is there for that. The prologues are quite a nice addition compared to the previous Tekken games. Now you know why the characters are entering the tournament. Plot holes filled. Some stories aren't as exciting as others and some stories (and endings) are intertwined with each other. But if you wish to unlock more characters, you have to play through Arcade mode. No ifs, ands, or buts about it.
The characters roster is small compared to Tekken Tag and Tekken 3 but I prefer quality over quantity. Kazuya Mishima returns (despite being killed off in Tekken 2) and he's better than ever! There are three new characters introduced in this game: Steve Fox a British boxer, Christie Montiero a female student of Eddy Gordo, and Craig Marduk a Vale Tudo fighter who's the target of revenge, They make a great and diverse addition to the roster and their fighting styles shine quite nicely amongst the other characters.
The gameplay is probably the weakest point in the game. Apparently Namco decided to experiment with the fighting system, adding things that didn't need to be added. It also confuses a lot of longtime Tekken fans. Namco should've just left well enough alone. The gameplay is also unbalanced which is bad if you play multiplayer. If you're gonna experiment on a game, do it right.
The music is nice and fits the stages well. It may not be what most Tekken fans are used to but it's good enough. Some of the tracks are a pleasure to listen to and I enjoy listening to them in Theater mode. The stages are realistic and very interactive. You can use wall combos and use the stage to damage your opponent. Very nice. That's one change Namco did right at least.
Tekken Force returns from Tekken 3 and with a vengeance. The mode is much better in this game and it's actually a challenge. The stages in this mode are based off of stages from the game and look stunning. The enemies have different classes and varying levels of strength and defense. At the end of each stage is a boss which is a character. To unlock one of the stages, you have to complete Tekken Force. The least Namco could've done was put a save feature for this mode so you won't have to start over every damn time!
Tekken 4 is the black sheep of the Tekken franchise and it's actually a good black sheep. I recommend this game if you're just beginning to play fighting games. If you're a long-time gamer, you may wanna stay away.