[dylz]

Yes, this is the big problem. Indie games usually run just fine in wine and don't do anything too advanced and just work out of the box; your biggest problem is probably going to be them installing stuff into weird places or directly onto C:\gamename.

The rootkit, driver signing enforcement, driver ACLing of anything it doesn't like, vulnerable drivers, all forms of emulation detection, failing any of those = permanent ban is a whole other problem.