More information needed.
Are you switching between wired and wireless networks on a regular basis? Home, work, internet cafes, etc..
Why Wi-Fi? Downloads/updates likely to be faster and more reliable if you use a wired connection.
For the most part you will need some script that runs in background that monitors the PC's network connection and allows updates:
IF connected wirelessly and IF connected to home wireless network THEN enable Auto-update as a start.
You will need additional script to specify game sites and games thus permitted to auto-update.
Likely to be very cumbersome and any number of small configuration changes could cause the auto-updates to fail.
What sort of update problem(s), if any, are driving the requirement?