You will get different opinions about your questions but the Retina display is a great machine and has great graphics and is super fast with the SSDs. It can run games well even on the Windows partition. The only thing you need to understand is that Mac is not a gaming computer and may not be the best for HARD gaming but the occasional game is fine. I occasionally play Call of Duty and it runs well on the Mac with great graphics. The new fan design helps to cut down on the fan noise but it still gets a bit warm with extended play. It's a much better laptop for gaming than the MBP.
Especially using Windows games?
If your going to play Windows games, a Windows 7 3D gaming tower is your machine.
3D games require a lot of cooling and laptops in general are not good enough to begin with, also their performance isn't too hot.
The Retina is all closed up, you open the machine you void your warranty and AppleCare so as the machine heats up and draws more air through it, dust bunnies collect on the cooling fins and will severaly affect it's longevity.
Not to mention pounding on the cheap bubble membrane keys etc.
Also Apple has a bad habit of chainging OS X every year, so it breaks the games and since they already got your money, are less likely to give a rats behind about some poor sub-section of Mac users.
So really you need a Win 7 tower, this way it's upgradable with newer video cards when they come out, you can clean the dust out, it has better cooling and Windows 7 will get support, as is, until 2020!!
SO you buy the game and it lasts for 7 years instead of just one year.
If that don't convince you, then take a look at this.
So 3D gaming on a Mac is just a temporary side hobby actually.