12mbps is absolutely fine, if you actually get those speeds. More likely, you'll receive something like 4-5mbps, which is sort of pushing it.
Online gaming has always worked fine for me, even with my 20mbps connection (which invariably ranged from 4-8 mbps), but the faster your internet, the faster you can download games, so that's a bonus. I never buy PC games at retail - all on Steam.







