Age of Empires (1+2) online

Aside from the obvious cleaning already mentioned, games from the Age of Empires II era had annoying copy protection that relied on putting garbage data in areas of the CD that weren't technically within the CD-ROM specification in question (ISO9660, I think?).

Your optical drive would be asked by the copy protection software to read out the data in these invalid areas to see if it matches what it's supposed to... the idea was that simply copying the files from one CD to another to pirate the game wouldn't bring the purposefully-bad sectors with it.

The major flaw with this plan is that some CD drives are "smart" enough to not bother reading the gibberish or attempt to error-correct it, resulting in a disc that won't validate as genuine, even if it is.

Yes, you can play AoE2 over a LAN with a Mac and a PC.