Microsoft Ultimate Word Games

Since Crosswords doesn't have a quickplay option or anything other good ways to gain experience, you will unavoidably unlock this achievement while working towards level 80.

Each Crosswords adventure mode map has 30 levels, and you'll earn 3 stars for each puzzle you complete, so you'll earn 50 stars well before finishing your first adventure mode map.

The achievement will unlock as soon as you earn your 50th star.