Sorry to necro this thread, but I figured I would add my two cents to this as it is very relevant to playing the game on a Macbook and on similar laptops in general. This post comes up under related searches on Google and may be of use to people browsing for information on performance without bias and too much tech jargon or flashy numbers that mean next to nothing on a real world level for most people. For a reference point; I play on a base model 2011 Macbook Air with 1.7GHz i5, HD3000 and 4GB of ram, 128GB SSD(Samsung Model). Take point that the newer model Airs and Pros completely obliterate what I am using from a hardware stand point and will yield better experience on all fronts, even the base models.
I initially wasn't sure I could play anything at all when I got it (school requirement) but quickly realized it was more than capable of most things, despite benchmarks and the various biased nonsense spewed out like garbage on internet forums that I had read prior to picking it up. I must say this, as long as you expect performance within reason of the hardware, you will be fine. By that I mean, don't come at the laptop all pissed off because it can't play games like Crysis 3 at 600 fps on max settings with 4k resolutions. Get a desktop if you want that kind of performance with those settings. Also, just because the GPU is integrated, that does not mean it will never be capable of running anything either, despite what people want you to believe about laptops and internal GPUs. iGPUs have come a long way over the past 3 or 4 years and will continue to do so. Sure, a base level desktop GPU may or will out perform them, but you can't just easily take an entire desktop computer with you when you walk to your friends house, go to school, hit the road for business or do anything that people actually need to do in daily life with minimal set up time. You especially won't get that for under 2.5lbs and the size of an actual 1 subject notebook that can be tossed in a bag and literally not be noticed.
For consistency purposes I play World of Warcraft at 720p, low settings (except high character detail, high particles, projected textures enabled.), capped at 20fps (you can set this by /console maxfps #), you can go as high as 30-55 depending on population density, but fans turn on. Fans are annoying, and I can't recommend settings that make them run at max. The system can absolutely run higher settings and resolutions but with varying mileage we should not get into as we are talking about the minimum comfort level here. The thing is though, with these settings I mentioned, gameplay is consistent the entire way through and there are no chokes, even in populated areas. Hell, the fans never even kick on because it runs cold. For most people, any choppiness you would normally expect to experience with 20fps is hardly noticeable on a 13 inch screen. If you have a trained eye, it's still tolerable due to the consistency in performance. This is a reality, not someone claiming it is better than it is. I have a desktop, and I play games at max with 60fps and you can't really tell the difference here like you would on a bigger screen.
If you're wondering about the other Blizzard games; they all run at 720p on low without fans ever kicking in, even with clutter.
Taking a quick look at my steam list for things that are currently installed, the following non Blizzard games are playable at acceptable rates with varying degrees of heat and fan noise. Almost all were on low settings with 720p but managed a consistent 20-30 fps. If they are windows only, I ran them on bootcamp. Some games maxed out, some games even offered laptop modes for greater performance. Again, these all varied but were playable:
Tomb Raider 2013
GTA IV and Expac.
Guild Wars 2
Batman: Arkham Asylum
Batman Arkham City
Every Assassins Creed
CoD: Modern Warfare 1 and 2
Dust: An Elysian Tail
Mark of the Ninja
The Witcher: Enhanced Edition
Shank 1 and 2
Trine 1 and 2
Ace of Spades
ALL Valve games, these performed to near perfection. Amazing work on their end.
Borderlands 1 and 2
Lone Survivor: Directors Cut
Two Worlds II
Many more that I can't add because it'd involve mentioning 500+ steam titles as I have played almost all of them at some point.
A newer Macbook, air or pro, WILL run this stuff with much higher frames and better settings than I used.
Overall, I am pleased with the ability to run these games while maintaining portability. Hopefully this is of some use to someone looking for the "Can I run this?" without fearing the typical ignoring of the question followed by the typical "NO YOU CAN'T! BUY PARTS FOR A WINDOWS DESKTOP PC AND BUILD IT YOURSELF BECAUSE WITH THAT BUDGET YOU CAN HAVE BLAH BLAH BLAH BLAH BLAH BLAH!!" drabble. One key thing to note here is that nearly every benchmark I saw online was wrong. So many websites claimed I would barely get 10 fps in some of these games, but I clearly had 30 or more in some cases.
Key things to take note of when setting a game up:
DO NOT max out the resolution; drop to 720p, on smaller screens, this is better and it's lighter on your hardware.
Turn shadows off and water to it's lowest settings if you can. Water and shadows are evil in this context.
Restrict texture filturing and AA to it's lowest option if possible
Do not play on recommended settings for any game, turn everything down to bare minimum, experiment and work your way up.
Drop the maximum fps limit, most games allow you to do this in console or settings. Some games require editing a text document, but it can be done.
Do not listen to people who tell you it's impossible to play a game on a laptop. Their idea of playable forgoes all reason and generally demands something no laptop is capable of. These people will never give you good advice on a laptop or they will ignorantly try to convince you that you need a 3000$+ laptop because it meets their expectations of what is "playable". /gag
On the other hand, the good guys at Lenovo do have gaming laptops that beat all competitors with their Y series laptops. They however are NOT ultra books, like a Macbook in the 11" or 13" line, have poor to average battery life, but do tear it up in gaming performance at about 100$ less than a base Macbook Air (they currently have 1 or 2 gt750m cards in the Y series laptops and frequently go on sale). I digress though, don't let those people scare you away from a laptop.
Good luck and happy computer hunting!