If I'm not very much mistaking this is the script you are looking for:
Says on their website that the script is from January 2010 and the games have been updated till 30th may 2012.
(script upd 27-Jan-2010) (games upd 30-May-2012)
I have no idea if the download links work (as I'm not filling in my email there, because I don't have interest in the scripts).
Another option I can also give you is on a certain big very well known torrent site (the one with a picture of a ship ^^).
Type in php arcade
as searchterm and you get 1 result back which is actually a free script for a change (so legally to download). It's already there since 2010 as well and only has 2 seeds so if you want to get it, better get it quick.
I'm surprised google didn't tell you this