Giant Punch
Giant Punch is Donkey Kong's Neutral B attack. It is charged by pressing the special move button; when it is fully-charged, steam will begin billowing out of Donkey Kong's head. A subsequent press of the special move button then allows Donkey Kong to deliver an incredibly strong blow. The charge can be canceled by shielding or pressing left or right while Donkey Kong is charging. If the control stick is tilted left or right, then Donkey Kong will stop charging and roll in the tilted direction. When fully charged it is like a faster, albeit weaker, Falcon or Warlock Punch. In Brawl, Donkey Kong gains super armor right before throwing the punch. It is weaker in terms of knockback if used from very close to Donkey Kong's hitbox and fully charged. If used just before the punch is fully charged, it has higher knockback than normal with the downside of giving no super armor.
In Melee and Brawl, this move puts Donkey Kong into a helpless state if used in mid-air. However, it has less ending lag in Brawl than in Melee and 64.
Reverse Giant Punch
When using Giant Punch in Brawl, if the control stick/pad is quickly hit in the opposite direction during the first few frames, Donkey Kong will turn around very quickly (there is no animation, he simply faces the opposite direction) and will use Giant Punch in the new direction. Every character (with the exception of Sonic and Samus) can do the same with their Standard Special as well.
