Game runs surprisingly well, despite it is 32bit. FPS are not a problem (usually around 100+ for me), but it heats a lot. Even rendering drains battery and thermal throttles less, than this, but it is managable. For Air, just take a minute break every like 40 minutes, Pro models should eliminate this problem completely.
/Tip: put two hexagonal shaped pencils under your MacBook, so heat can escape from under laptop, it is like small budget coolpad/
Have been experiencing some minor graphical glitches with some settings, like not rendering small decorative object when looking through a portal.
Most of the time I have been playing on low details (although it has power to play on Medium/High), fullscreen 1680x1050px, triple buffering VSync, 2xAA.
Happy to answer all questions about topic,
AP