I play for U-17 (15y) and have joined (1) offline tournaments
Hidden achievements unlocked by me:
CASTLE VICTORY! : https://www.chess.com/game/live/118376903179
Juggler : Just see daily games list
Chess Marathon : https://www.chess.com/game/live/96380979721
Searching for Bobby fischer
Quick knockout : https://www.chess.com/game/live/86342356271
Nick of time : https://www.chess.com/game/live/81440853826
Full house : https://www.chess.com/game/live/85572091783
Pen pal