Here is the full list of all 12 Braid achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Travel all the way across World 5.
Travel all the way across World 6.
Fit together all the world 2 puzzle pieces and align the puzzle in its frame.
Fit together all the world 3 puzzle pieces and align the puzzle in its frame.
Fit together all the world 4 puzzle pieces and align the puzzle in its frame.
Fit together all the world 5 puzzle pieces and align the puzzle in its frame.
Fit together all the world 6 puzzle pieces and align the puzzle in its frame.
Complete the game.
Complete a full speed run, beating the challenge time.
Travel all the way across World 4.
Travel all the way across World 3.
Travel all the way across World 2.