1. Complete Classic Mode on Normal Difficulty or higher in 12 minutes or less
2. Complete 70 Vs. Matches
3. Get Captain Falcon to join your party in the Subspace Emissary
As Captain Falcon is a racing pilot, it only makes sense that you have to race through Classic mode to earn him. Use the character you can get the quickest KOs with and be merciless with the damage. This is no time for a lot of dodging and item grabbing. Just hunker down and juggle your foes like there is no tomorrow. You can also get him by getting him to join your party in Subspace Emissary. If you want to do this the slow way, there's always the Vs. mode option. Captain Falcon is another character not blessed with long range attacks, so a good ranged barrage should take the fire right out of him.
Every man dies, but few truly live. Live your life to its fullest, every day as if it were your last.