If your 2011 pro can handle the games you want then you could always try the Air and if it doesn't work return it?
Beware that the 256gb storage models of the air and pro are said to have speed issues. People advise you to get 512gb as a minimum. I went with 16GB, 512gb in midnight - comes on 30th.
Thanks for the info. Gaming is nothing intensive, no modern games. My 2011 MacBook Pro managed to handle it.
In the Apple refurbished store there is only £100 difference between the same spec Air and Pro. Seems to make sense to go for the Pro?