Does your Mac meet the requirements for Steam:
Intel Mac,
OS X version Leopard 10.5.8, Snow Leopard 10.6.3, or later.
1GB HD space
Yes.On steam it is free for PC and MAC.
No. Steam games run on PC/mac and not on Sony PS4 (or nintendo or xbox) at all.
Steam will be available for the Mac sometime in April (See links below).
Civilization 5 is powered through the Steam system so you will need to install Steam and create an account to install and run the game. (See links below)
You may wish to check your system configuration such as installed RAM. Try troubleshooting the lag issue, is it only when you run 'Steam'? Does your Mac lag with any other applications? It may be a bug in the version you have, but it may well just be a RAM issue that needs fixing by adding more memory modules to your Mac. But nonetheless, you should contacting support for the 'Steam' application.
Buy it through steam.
You cannot run Mac on Windows XP. But you can run Windows on Mac
There is a Mac version of Age of Mythology which can run on a Mac computer.
Yes you can.
Check steam tech support.
an auto run inf on your mac*
No, because you are not using Steam to play the game, you are only using Steam to verify the game and to use the multiplayer parts of it. If you have a Mac version DVD/CD of the same game then you could still use it on steam if you register it on Steam.I THINK if you bought the Windows game on steam they will let you download the Mac version on the same machine. They have the full instructions on their web site.