Here I'll show you the basics of counter atacking and defending your goal from super shots. There are some types of shots: the linear ones, the ground ones, the kamikaze ones, the up to down ones and the other ones (alien, robot, asura, france, UK)

Linear shots
Linear shots are that ones witch go horizontaly. The best way to block them is counter attacking. Just kick the powered ball and you'll counter attack. If you are using a caracter with this type of shot, you should jump to use it, or the ball can hit your opponent and go over you, making a goal for the opponent. Ex: South korea, netherland, ireland, china, cameroon.

Ground shots
Ground shots always go in the ground, even if you hit the ball in midair. To defend them, get the right timing to kick the ball. Kicking the ball will result in a counter attack and you can defeat the opponent. If you use them you shoul get closer to the opponent and to the goal in order to be close to the ball when the ball hits the opponent (nigeria) or push your opponent directly to the goal (italy) Ex: Nigeria and Italy

Kamikaze
German and spain have ones of the best power shots. To block the balls, you cant counter attack, so its like throwing yourself into the danger. In germans case, just jump in front of the balls. In the spains case you have to see if the first ball could enter in your goal and if so, jump in it and jump again in the second ball, if not, wait to jump only in second ball. After blocking the second ball you'll have to dash forward and there is a chance of the last ball get in your opponent's goal. If you are using german, use it close to your enemie and away fom the goal, like in the middle of the field. If you are using spain use it in your side of the football field.

Up to down
These shots get from an upper position and go to the ground. Just jump and kick, but its good knowing the angle of the shot. If you are using it dont get too close of the goal or you'll miss it. Ex: brasil, canada, chile, star (that last japanese guy)

Others:
Asura: to block him, you must jump in front of the ball and, if possible, kick it, like in a linear shot.
Alien: you should turn on sounds and music and listen to him speaking, so you can know if he'll use tornado, ice, fire eagle or robot.
Robot: to the missle shot, you should get under the missles and dash backward and jump to hit the ball. In the other shot just jump and kick.
France: if your opponent use it in mid-camp its a guaranted point for him. Try to avoid this and see if he is shoting at your side (the ball will get in mid camp again) or his side (calculate, get in the place the ball will get out and try to kick it.
UK: UK have the red laser shot. Just get close, but not into the laser area and when you see the ball, dash backward and jumpin the ball.