The Anniversary Update Title update for Rocket League has 6 achievements worth 250 gamerscore.
Trade In five items of the same quality to receive an item of the next-highest quality
Complete all placement matches in any Competitive Playlist
Score or Assist a combined 30 goals or assists in Casual or Competitive Online matches
Head to Champions Field and complete an Online game
Equip a Very Rare Item and complete a game in an Arena with turbulent weather
Trade and receive one or more items with another player in a single transaction