I've sort of admired, but never gotten hugely into any SF game--although I've dug into SFII at times--and it doesn't look like IV is going to change that pattern. The fighting engine in IV feels rock solid--probably too rock solid for my spastic gameplay style: it's all about "zoning" and all that, forcing your opponent into specific spots where you have an advantage and can counter in a chess-like fashion; I know that sounds weird but that's how it feels, and personally I prefer my fighting games on the wild side.
SFIV has hi-def (well, 720p anyway) 3D graphics, but still plays in the traditional 2D manner, has six attack buttons, etc; it definitely feels like a Street Fighter, something that's hammered home by about half of the two-dozen-strong cast sharing the same special moves (fireball, uppercut, yawn). The old characters look oddly blocky and beefy, and are now rendered in a heavy dark cel-shaded, sort of colored-pencil-filtered style. They also threw in four new characters, but these are horrible, horrible designs: a big fat guy--by far the most entertaining--a tiny luchador (who cooks...), a I think kick boxer who's supposed to be French but doesn't have an accent, dresses like a soccer player (???), and has a command throw that the CPU just loves to abuse, and a sexy woman wearing a suit and tie, total rip-off of Vanessa from KOF, except that she looks dumb and wears her hair in a bizarre pony-tailed pompadour. I've never been a huge fan of SF character designs, though--pretty much the only one I can stand to play as regularly is the strategically limited Cammy (Cannon Spike, Cannon Spike, Cannon Spike...), although I do like Zangief, but can only rarely bare trying to handle his slow pace and 360-degree throws.
Characters in this edition of the series generally have fewer special moves and supers (everyone really only has one super, I think, and an "Ultra" version of it), and the game is relatively conservative when it comes to combos and pacing; the emphasis is on a relatively slow, meat-and-potatoes type of gameplay, which I'm all for, except that SF's lack of movement options and super-punishing anti-airs turn it into a really nasty, controlled zone type of thing, as I mentioned before, and that just isn't my bag.
The backgrounds are generally ugly or dull, sporting a sort of soft pastel color scheme and, like the characters, a blocky look; they really just aren't that interesting, and modern hardware should definitely be capable of rendering something much more beautiful, or at least interesting.
I'm mostly a single-player type when it comes to fighting games, and SF's single-player is not so great. The AI is actually a little more forgiving in terms of anti-airs than it has been in the past, which is nice--you can actually land a jump-kick with decent regularity--but it still has the standard SF dull and robotic feel to it. The boss is usually not that tough, although sometimes he decides to go through a chain of special moves that just pulverizes me; but no, the thing that annoys me about him (aside from his command center stage being really ugly and lame) is he's yet another of these "let's not come up with an actual personality, design, and move set, instead we'll just make him like a naked cyborg amalgamation of a bunch of characters already in the game" type of things.
The game's online mode seems to handle lag quite well. Matchmaking results in some bonk-out or error way too frequently, but once you actually get in and connected, the play is pretty darn smooth most of the time. An update added a championship mode that I guess is some sort of open tourney system where you go through a series of cascading fights that aren't limited to just a small starting group somehow--haven't really tried it. Winning matches gives you points, which look cool and maybe do other things I'm forgetting, and badges, and can unlock custom titles and icons, which is pretty nice, although customized costume options would have been nicer--there were downloadable costume packs available for a few bucks each, but most of these weren't all that great (Dan's boxing practice costume is awesome, though), and far too many of the male characters were given bizarre giant rope butt-bow outfits. Mm-kay.
I do find the online a bit intimidating though because if you lose a (ranked) match, you lose points, and this just feels like a big downer, at least for those of us who aren't sure if we're going to win more than we lose. Capcom said they were trying to make this SF more "approachable" for non-super-hardcore types, but that really only seems to have meant that there weren't that many moves per character, and the default single-player difficulty curve is pretty mellow; the moves that are there are mostly just as hard to pull off as before (some of those old moves are just nuts!), the zone-heavy gameplay is extremely unforgiving to those who haven't mastered individual character strategies and move sets, and being constantly stripped of points when losing is a sure way to keep the newbies sucking at the bottom of the pile.
Oh hang on, I didn't finish talking about single-player. Aside from the Arcade/Story mode (the less said about the cheap-anime-cutscene-driven "story," the better--it really is horrible and brain-hurting to the point where the game would actually have been better off without it), there other thing you can do by yourself is a "Challenge" mode. There's a Survival type of challenge thing, but instead of normal Survival, ie fighting random people 1-on-1 until you die, you face a predetermined array of foes with special rule sets for each match, such as altering health, damage, etc, and for me these reach a cheap and un-fun stage very quickly. Just have a regular Survival or Endless mode, damn it!
There are also combo challenges for each character, which require you to execute more and more difficult combo moves against a training dummy. I am really, really bad at these, and just can't get into them at all; I guess they're bragging rights for people who love to practice combos nonstop, but really how many people is that? Oh well okay I guess they might also be good for teaching hardcore players additional combos. Anyway they're lost on me, and on the whole the only reason I went back to the game for single-player more than a few times was as warm-ups so I wouldn't lose more points than I had to when going into multiplayer.
I was really excited about SFIV at first--had some addictive late-night multiplayer sessions, and rushed out and modded my joysticks (see entry 1270) with real Japanese arcade buttons, even--but after realizing that there's only one character I can bear to play, AND that she's extremely vulnerable to anyone who knows how to take advantage of her weaknesses (fireballs and charge characters, for instance), AND that I WILL face a nearly endless succession of shotos (fireball, uppercut, repeat) in multiplayer, AND that there's really nothing I like about single-player, well, the thrill has pretty much worn off. Seems like a great addition to the series for Street Fighter fans (well at least those who can stand the chunky 3D style and the return to SFII-ish conservative gameplay), maybe not so much for the rest of us.
Going back to this game after years and years--and having played a bit of SFV in the meanwhile, not to mention SFIII, KoFs, Virtua Fighters, etc--I was surprised by just how bad the movement feels here: the jump physics are unnatural, and a lot of moves speed up at odd points; it just doesn't feel smooth or intuitive at all. And yet people played SFIVs for years and years at a very high level, and it kind of kicked off the whole e-sports thing for fighting games. But it feels awful to play.
And after the baby doll version of him in SFV, I had totally forgotten how nasty CPU Zangief is in IV! Yikes! You can see him crush me repeatedly in my bad Ryu play-through: