You can download Braid from any of these sites:
All sites have free demos; I recommend trying the demo first, not only to see if you like the game, but to make sure it runs well on your computer.
There have been reports of a few problems and I am ironing these out, and shipping off new versions to these publishers as the fixes come in.
We had a rough few hours for the web site here, but the hosting company has upgraded the bandwidth so hopefully it will survive the stormy waters.
Thanks, and I hope you enjoy the game!