I dont know the minimum specs, but I would have thought nearly any computer on the shelf today would run it. the exact specs would depend on your game. I guess if it runs DirectX9 it would be enough.
I'm sure Jlnr will be around to give a more exact answer
By jlnr (dev)
Date 2010-08-03 23:59
You need 3D hardware acceleration, which every machine should have by now.
After that, it's simply a matter of how much computation your game needs. Unlike other language/toolkit combinations, Ruby/Gosu performance starts off pretty good, but can come to a halt quite quickly too. Try to keep your game logic simple. (Good that you are not a previous Java programmer.)
(This applies to Windows and OS X, Linux seems less predictable to me.)
