If you're good at SF, then yes
If you aren't brilliant at these types of game, then it's worth a buy, but probably not just yet
The only reason I wanted this game is to bring back memories of SFII on Megadrive, and it did just that, I was taken back 10 or so years to playing on my brothers megadrive against my brother, and fighting as the "green guy" or the "Fat guy" because they looked dead cool. My brother was obviously the best characters (Sagat, Ryu). I put SFIV Into my 360, see the green guy and fat guy, and I get excited
Arcade mode is allright.. no real story behind it, other than the first movie which shows you why they're fighting, and the end movie when it shows what happens as a result. You face around 5(?) other fighters before you face your rival. The first 5(?) are quite easy, the rival fight gets quite hard. After you fight your rival you face Seth. Now this guy is difficult. Even on Easiest difficulty, it's still quite a fight. I managed to do it, but my god it was hard to do. Personally, I'm not that good at these sorta games, you go onto arcade mode, the default setting is "Easy", let me tell you, there is nothing easy about it, well not for me anyways. When I first went onto arcade mode, I went for my old pal green guy, on default difficulty, and get absaloutely raped. I decided thats because he's shit, so go and pick fat guy. I won the first fight, but got raped in second fight. Eventually I go through loads of characters untill I found one that suits me, Balrog. I put difficulty onto "Very easy" and it was just right for me, losing some fights etc, but finally I face seth and beat him after about 7 attempts.
Online mode, so many people playing, so little availible games. Make your own match! people join quickly, your sorted. Now let me warn you, online mode is fecking well hard. I've won 5 of 23 fights. So yeah, it's hard. However, it is good. You unlock different "Titles" that you can use to put above your name, you unlock better ones with the more fights you win, or the more times you do certain things. You also unlock "Icons" which follows the same format.
Challenge mode, I've not really started yet.
Overall, its only probably worth picking up, allthough it is hard, and best suited to those who are brilliant, it's still a kick-ass game, and fun as hell.
Plus, it is fecking STREET FIGHTER!