Some users of high-end Nvidia cards on Windows Vista 64 and Windows 7 are having a problem where the game doesn’t sync to vertical refresh (they get visible tearing in-game).
I am going to put out a new version today that fixes this; but in the meantime, you can use this command-line option:
(for example, adding it to the Braid shortcut) which should fix this problem in the meantime.
Another option is to set forced vsync in your Nvidia control panel.
If someone who has the problem can verify that the command-line option works to fix it, then cool.