ACHIEVEMENT - HOW TO UNLOCK Air Kill - Kill an opponent in the air. Destruction King - Win ten online destruction games. Don't touch me! - Win a race without getting killed. Firebooster - Kill ten opponents with every Fireboost type. First Steps - Complete all challenges for one character. Massacre - Kill ten opponents in one race. Online Endurance - Finish fifty online games. Online Racer - Win five online races. Serial Killer - Get 100 Kills. Threepeat! - Complete all challenges for three characters. Triple Kill - Kill three opponents in 5 seconds. Winner - Complete all challenges for all characters.