(Joystick commands are for when your character is facing right. Reverse them when facing left.)
How the super combo gauge works
The super combo gauge is located in the bottom left corner of the screen for player 1, and the bottom right for player 2. It is empty at the start of a round.
By attacking the opponent, the gauge will fill up. Special moves are a good way of filling it up quickly, but different moves will add different amounts to the gauge. For example, doing Ryu's shoryuken will add more to the gauge then doing a hadouken. The gauge will also fill up a little when receiving damage.
When the gauge is completely full, the word "SUPER" will appear, and you can use your character's super combo move. The gauge resets between rounds so don't bother trying to save a super combo for the start of the next round.
Blocking
To block, hold back on the joystick. To block low attacks, hold down back on the joystick. You can block just about anything apart from throws and command throws, such as Zangief's spinning pile driver. You will not take any damage whilst blocking standard punches or kicks, but you will take a very small amount of damage when blocking special moves and super combos. You cannot block in the air.
Jumps
There are three jump types in the game -holding up on the joystick will have you character jump straight up, holding up forward has them jump toward the opponent and holding up backward has them jump away from the opponent.
Throws
Each character has at least one throw technique. Throws are done by getting close to the opponent, holding forward (to throw them forward) or backward (to throw them backward) and then pressing either strong punch, fierce punch, forward kick or roundhouse kick. It depends on the character for which button you need to press, for example, Chun-Li can only throw with the strong and fierce punch buttons.
Tech hits
New to Super Turbo are tech hits, which are also known as throw tech. When you are about to be thrown, you need to input as if you were going to throw the opponent, and you need to do it quickly. So in the example to the left, player 2 needs to hold left or right before pressing either strong punch, fierce punch, forward kick or roundhouse kick. When you tech hit a throw, your character will take half as much damage than usual and will recover in the air, landing on their feet.
Stuns
If you repeatedly manage to hit your opponent with attacks within a few seconds, they will be stunned. This means that they will briefly be unable to move or block, so you've basically got the chance to get in a free combo. If you are stunned, press every button to shake off the stars quicker.
Reversal attacks
From the SRK Super Turbo guide:
"A reversal is defined as: any time you go from a non-neutral state directly into a move (normal, special, super, or throw), without ever going to neutral state. A non-neutral state is any state that your opponent inflicts on you: block stun, hit stun, getting up after being knocked down, dizzy, or being knocked out of the air. Only throws, special moves and super moves work as reversals."
Check the example above -Honda hits Balrog, but Balrog immediately strikes back with a dash punch. Any special move can be used as a reversal, whilst some characters can use their super combo moves also.
Juggles
Another new feature to this game are juggles, which are basically air combos. Everyone but Zangief and T. Hawk have moves which let you juggle the opponent, on the example above, Ryu uses his new jumping forward strong punch twice to juggle combo Bison.
Super Combos
The other main feature of this game are the super combos. You can see how the super combo gauge works at the top of this page, as soon as the gauge is full, you can use your character's super move. These moves do massive amounts of damage if they hit the opponent. If you finish the opponent off with a super combo, the background will display an explosion for a few seconds.
Meet the Bosses
BALROG
Balrog is tougher than in the previous game as he just seems to be that much faster. His dash punches are something he loves to constantly do, and he's gotten better at avoiding projectiles via using his shoulder butt. His main weakness is in his apparent inability to block jump in attacks, so try using those. He will often dash punch straight into projectiles, so keep throwing them out and see what happens.
VEGA
Vega is tougher than ever, and he will keep you out of the air with his jump kicks. His new back flip move is something to be wary of, especially as he'll often use it as he gets up from being knocked down. CPU Vega no longer uses the escape back flip anywhere near as much as in Super Street Fighter II, so he's not as stupid as before.
SAGAT
Sagat is now the easiest boss in the game because he still has those tiger shot patterns. If he throws a high tiger shot, he will most likely follow it up with a low tiger shot, giving you plenty of time to jump in and attack. As ever, don't jump in randomly at him, as you will get hit by a tiger uppercut.
M. BISON
Bison has been made smarter as he is now much better at using his kick attacks, along with his habit of getting lots of throws in. CPU Bison now also seems to be very good at using the head stomp move and can use his kick to keep you pinned down. If he head stomps you, he won't usually follow it up with the extra strike so you can usually get a hit on him as he lands.
AKUMA
By meeting certain requirements, you can make Akuma appear to challenge you. Akuma will appear and defeat Bison with his shun goku satsu move, and then he will fight you.
Akuma is the strongest fighter ever and has all of Ryu's moves, but his are far more powerful and do lots more damage. He also has a couple of extra moves over Ryu, such as the ability to throw two fireballs whilst in the air, plus he can also teleport. His teleport lets him go through attacks with ease, including projectiles.
He can juggle you with his hurricane kick and will often follow it up with his dragon punch. He also has a flaming fireball, which is extremely fast and can do multiple hits. If you manage to throw him, he will almost always tech hit out of it, and in the unlikely instance of him being stunned, he will recover straight away. He can throw his fireballs so quickly that trying to jump over them and strike him before he recovers doesn't really work, as he'll be ready for you before you get the chance.
Akuma is one of the hardest Street Fighter boss battles ever, and I really don't have any advice in how to take him on other than saying that if you've made it this far, then you must be skilled already -good luck!