Old games, like Sid Meier’s Civilization V (photo above), will run properly even at 2880×1800 resolution. Most recent titles will have to run on 1920×1080, though, since the GPU can’t handle heavyweight 3D graphics at native display resolution (in fact, I think only a SLI/Crossfire system can). My title of choice to test gaming on Windows 8 was Hitman: Absolution. I started playing this on my old iMac and I noticed a great improvement on both gameplay and graphics quality. It runs well on Medium settings at 1920×1080. Although not photo-realistic like Ultra settings achieved by top-tier desktop systems, it’s enough to properly enjoy the action.
The only problem I see with gaming on this laptop (in fact, any laptop), is that the fans run at full speed and the noise is annoying. Even though Apple came up with a fan design that produces much less noise than your average Alienware laptop, you can still hear it if you play without headphones. On my iMac, I used to hook up a Bose Companion 5 speaker set to it for gaming, and it worked fine. Now, I have to play with headphones — my Bose QC-3 noise canceling system works fine to cut the fan noise.
Overall, gaming is enjoyable on the MacBook Pro with Retina display. Just don’t play resting the notebook on your lap — it gets very hot!