Villain is unknown. Do we gambooooooollllll?

Hero (Button) ($614.30)
SB ($224.35)
BB ($70.80)
UTG ($119.30)
MP ($144.20)
CO ($237.30)

Preflop: Hero is Button with 7, A
2 folds, CO bets $3.50, Hero raises to $12, 2 folds, CO calls $8.50

Flop: ($25.50) K, 9, 3 (2 players)
CO bets $225.30 (All-In), Hero requests time.