Here is the full list of all 10 Drawful 2 achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Play 50 games
Get more than 50 likes in a game
Play with 10 or more Audience Members
Enter a drawing with more than 50 lines
Enter secret title in game
Play a game with User Generated Content
Got a streak of 3
Use both colors in a drawing. It’s easy!
Choose a decoy answer
Fool every other player with a title you write.