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.
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
Reversal attacks gave been in the previous games, but now the game actually recognizes them and will display a message on the screen whenever one is done, along with giving you a points bonus.
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."
Example above: Ken sweeps Ryu, so I do Ryu's shoryuken motion as he gets up and he does the move as he is up.
Meet the Bosses
Arcade mode now consists of you fighting 8 random opponents, then you'll move onto the four grand masters.
BALROG
Balrog's AI is still fairly stupid in this game, and the old tactic of sweeping him repeatedly will still often work. However, his new shoulder butt move is something to watch out for, as he can hit you out of the air with it, or he can use it to pass through projectiles. His dash punches are still as fast as ever, but overall he is still pretty easy to beat.
VEGA
Vega's AI has seriously been toned down -he's really dumb in this game! The main advantage you have is making him do his flip move. Trying knocking them down, then doing a fierce punch or kick next to him as he gets up. He'll back flip 99% of the time, which doesn't hurt you and sets Vega up to be attacked again without him being able to do a thing about it. He's even easier than Balrog in this game.
SAGAT
Sagat hasn't changed much, meaning that his silly high tiger shot followed by a low tiger shot and repeat pattern is back. Once he starts throwing tiger shots, just jump in and attack, but don't take too long as he'll use his tiger uppercut. He will always use this move when you jump at him, so don't do random jumps unless you want to take a hit.
M. BISON
And up last is Bison, who has also become a bit less challenging than in the previous games. He'll often use his head stomp, which can easily be blocked and countered. As usual, he tends to start spamming his psycho crusher when weakened, so watch out for it. He's still the most difficult boss as his attack patterns are less predictable compared to any of the other bosses, and he's still good at throwing you.