Here is the full list of all 14 Scrabble achievements worth 1,000 gamerscore. It takes around 1-2 hours to unlock all of the achievements on Xbox One.
Score over 50 points in one turn.
Complete one match in any mode.
Score over 225 points in any mode.
Use at least 2 types of Premium Squares in one turn.
Spell at least two words in a turn.
Score a Bingo.
Beat the Very Easy AI.
Win 5 matches in Quick Play.
Score over 325 points in any mode.
Beat the Hard AI.
Beat 3 Very Hard AI in one match.
Make a word in the last 5 seconds remaining in your turn in any mode.
Use an Emoji in Multiplayer.
Spell the word "SCRABBLE" on board.