The original Street Fighter was a pretty mediocre implementation of a brand new game genre - the 1-on-1 fighter. Fortunately, it was successful enough for a sequel - Street Fighter II swept away the arcades with its incredible combination of tight gameplay and the way in which it rewarded skill while allowing people to compete head-on in a fist fight without actually getting hurt themselves. It was a smash hit and literally changed the face of the arcade forever.
That was 17 years ago. In the intervening time, there have been dozens of sequels and spinoffs - the Alpha series being a highlight, while the first attempt to bring the game into 3D (Street Fighter EX) was rather less successful or critically acclaimed. It's been ten years since a sequel to the main Street Fighter branch (Street Fighter III Third Strike was released in 1999) and this time around it's seen only limited release in the arcades before heading home to PS3 and 360.
Street Fighter IV recreates the original 2D mechanics (there's zero depth in the play area, the game plays out entirely on a 2D fighting plane) although now the graphics are in visually stylized 3D. More than just a graphics change, this new style results in super smooth animation - which has more than just a visual impact. Previous titles allowed the hardcore players to trigger moves based on precise frames of animation - determining exactly which attack to do, and when, depending on what their opponent was doing precisely at that moment. The result is core gameplay which is technically the same (you can still interrupt attacks, etc, depending on what the other player is doing) but which takes some adjusting to thanks to new animation data.
Another impact of the switch to 3D characters is costume variety - there are already downloadable content (DLC) packs that significantly change the look of your favorite fighter. For a fee, of course. Additionally, special attacks or intro / ending sequences utilize a camera which moves in 3D to show off the stylistic visuals. It's simple stuff but it definitely adds to the appeal - even if in a small way.
There are some significant changes to the core gameplay - aside from the change in timing, of course. The most significant of these is the focus attack. By holding down MP and MK, the player is able to absorb an attack from their opponent - releasing these buttons unleashes a focus attack (the longer you hold them before releasing, the stronger the attack). This new attack can be cancelled by dashing (double tap forward or back) and the focus attack itself can be used to cancel special attacks, allowing for some seriously complex combinations once you get skilled with the system.
The second most significant new system in Street Fighter IV is the Ultra Combo. Unlike Super attacks, which are powered up by doing special moves, Ultra attacks are powered up by having the crap kicked out of you by the other player - think of them as a revenge move, designed to tip the balance back in your favour. These attacks are devastating, doing massive amounts of damage - should you manage to pull them off.
Street Fighter IV is also tightly integrated with an online system. With a 1-on-1 fighting game, it should come as no surprise that the game is clearly geared around multi-player. Even so, the depth of the online system in SFIV is truly impressive. In addition to having massive amounts of unlockable content that revolves around playing online, you can setup the game so that people can challenge you at any time - "here comes a new challenger!", just like in the arcades! This incredibly clever system means that if you want to play online you don't need to sit around bored in a lobby - just go play and someone will jump in when they're ready!
The system isn't quite perfect, however, mainly because you have to be at the main menu to turn it off - it can be a bit frustrating to get up to the end of a single player game only to constantly be interrupted in the final bout by challenges. These challenges will reset your single player fight even if you turn them down. You also don't seem to be able to have a second player join you locally if you're in the middle of a single player game and your game is configured to be remotely joinable. It's an odd quirk indeed but no game-breaker.
Online multi-player is largely lag-free - so long as you accept fights with 3 "bars" (a measure of connection quality, from 0 to 5) or more, you'll feel like you're fighting on the same machine. At two bars you can feel slight delay in your actions, at one or none things can get pretty freaky. Still better than many other online games but certainly not ideal for a twitch fighter. Stick to 3 bars and above and you'll be blown away by the performance.
Graphically the title does an incredible job of looking like the old game come to life. Any screenshot you see has an amazing similarity to the old game, yet SFIV is genuinely 3D. The animation is kickass (literally) and the characters look incredible from every angle. The backgrounds are solid enough and the presentation, whilst a little inconsistent, more than does it's job.
The character roster is very deep, although you'll have to spend a chunk of time playing through single player to unlock them all. There's also talk of adding in other characters (such as Dee Jay and T. Hawk) through DLC. The four new characters (El Fuerte, Crimson Viper, Rufus and Abel) all definitely add their own vibe to the game - the jury is still out as to just how balanced they are. El Fuerte seems to have incredible ability in the air, for example. As with any new characters to an existing series, they're going to take some getting used to - whether fighting as them or against them. As it stands right now, there are 19 characters in the game.
The controls are tight but, as with most fighters, playing them on a standard controller (for any system) is far from recommended. Fortunately, the PS3 is extremely compatible when it comes to working with non-standard controllers. For example, most of this review was conducted using a homemade arcade stick adapted from a Super Nintendo controller connected via a PC USB adapter (!) - which works perfectly. So if you've got access to an old PS2 stick or similar, you should be fine (your mileage may vary - you should check it out before spending any money just in case). Alternatively, if you've got money to burn, you can get a very nice stick made with arcade parts especially for Street Fighter IV for... four hundred dollars.
When all is said and done, Street Fighter IV is the deepest fighting game ever released. It's combat engine is incredibly in depth, with even the hardest of the hardcore likely to be discovering new possibilities years from now. Even if you're new to Street Fighter, you can get up to speed with the training system and there's plenty of challenges to keep you entertained offline, with the best online implementation ever seen for those that like to spar over the internet. It's the best fighting game ever - if you like good games you owe it to yourself to check this out; if you like fighting games you simply have to own this.