Here is the full list of all 15 Boggle achievements worth 1,000 gamerscore. It takes around 40-50 hours to unlock all of the achievements on Xbox One.
Find all the possible words on a grid.
Score more points than possible. Magic!
Finish first in an online game.
Reach the Diamond league.
Find 1337 words.
Find 3000 3-letter words.
Find 2400 4-letter words.
Find 1500 5-letter words.
Find 600 6-letter words.
Find 210 7-letter words.
Finish first in 100 online games.
Play 500 games online.
Enter 20 words in a row without any errors.
Find 80 words of 8 letter or more.
Play 500 classic games.