I didn't see this covered anywhere and one of these days we will release a patch for our game, so I thought I would ask.

How do games usually patch on the Mac? I want something that is simple for the user, that overwrites the changed files, and leaves everything else alone.

Just as reference, the game itself was shipped as a simple dmg.

Sparkle library. It checks for updates, notifies the user when one is available, downloads new versions in the background, and installs them when finished.

Then again, if your game is 200MB, you probably won't want to download the whole thing again, so you're probably better off coming up with something yourself.

http://sparkle.andymatuschak.org/

I swear by Sparkle. The best part about it is that you can get by with close to zero code work. At any rate, I managed to hook it into an already-on-the-market product in less than 30 minutes.

Sparkle looks interesting. It looks like I would have to update the entire game though (in our case around 90MB) which would be a pain.

Any other good options?

Not really.

Apple includes "bspatch" with Leopard, so you could easily roll your own binary patcher with that, but it would be a bit of work.

Ryan Gordon uses "MojoPatch" ( http://icculus.org/mojopatch/ ) for UT2k4 but the UI is (or was) a bit nasty...