Yeah. FTP.
Get a free web host that allows anonymous FTP access (download-only required), and make it so your game/program automatically downloads the following:
- A version.txt file (just contains the version number)
- And your game files.
The game will know what it's version is, and you simply need to check whether the version information corresponds with the data inside version.txt. (You can update version.txt manually whenever you update your game.)
If version.txt <> currently-running program version, re-download the game as it will have changed.
How's my typing? Phone 0800-GO-TO-HELL