My new dvd game is asking for a POWERPC processor, but I don't have it, cause mine is Intel. What should I do?

If your Mac is capable of running Snow Leopard (10.6.8), then install it on an external drive, or separate partition of the internal drive. Then you can boot to SL to run that game and any other PPC apps.

If your Mac came with Lion, then you're pretty much stuck. Your options are to look for newer version of the game that is Intel native, purchase an older Mac that can run it if the company has no Mac Intel version, or install Windows 7 on a Boot Camp partition to run it as a Windows app.