Many flaws, but fun all the same. Online is enjoyable, offline is another business....
At first, Street Fighter is a real frustrating experience for new players. Online you will get destroyed, and many times by people who spam the same move over and over again. So you hop to offline, and get destroyed on the standard difficulty. Bumping it down to 0 stars, the game is still very difficult.
But once you have gotten the basics down, Street Fighter becomes pretty fun. The fighting system is not nearly as advanced as say DOA4, but no one should expect it to be. Each character has 3 special moves, most executed the same way. Certain characters have big advantages over others, which can get very irritating. All 12 characters are a bit different, but if you play online you'll only encounter a few.
One word describes the online mode: addicting. You can get into matches quickly, as many players are taking part in fights. However, it is recommended to create your own match, as otherwise you'll time out about half the time you try to join a match. Match-making is quick, and you can go game-to-game-to-game with ease.
Until you know how to beat players who spam cheap moves, online can be frustrating. Playing for a long time does tend to lower your reputation, as players get very angry and give you bad reputation for no reason.
The achievements are almost half-half online and offline. The online ones will come with time, but some of the offline ones take raw talent. Overall, a good spread of achievements that were thought out.
At $10, Street Fighter costs a bit much. Too bad games only really come at $5 or $10, because something in-between would have felt more appropriate.
Overall, Street Fighter will please those you use to bash friends on the SNES, or at the arcades. The game can be frustrating for new players, but even with all the flaws, it still is fun.