You can unlock Falco one of three ways.
1. Play 50 Brawl Matches
2. Have him join in SubSpace Emissary
3. Complete 100-man brawl
Chat with our AI personalities
play alot
nope.
krystal is not a playable character in brawl
Finish the 100 man melee mode then defeat falco.
first complete 100 man melee then falco will appear