Some people may feel that standard attacking is a little limiting. There are only so many attacks each character can perform. Because of this, Super Nuke Bros. Melee focusses chiefly on another type of attacking.
Special Moves are different to normal attacks. They are defaulted to the S button, and unlike normal attacks, change depending on which direction is pressed. This means that each character has 4 of these attacks, one for each direction (up, down and side) and one for pressing the button with no arrow keys selected. Let me run through these moves in a little more detail.
First, the Standard attack. This is the attack made when you press the special button with no directions. Usually, this is a ranged move, or a chargeable one. It either spans a good distance, or deals a lot of damage. Quite often these seem rather useless, but in the right hands, they can be very powerful.