If magnetmix files download very slowly, it can sometimes point to an ISP shaping bandwidth. I can't find any info about ppc...what does that stand for?

Check out this thread for tips about configuring LW.
A few things to consider while configuring Limewire for optimal performance...

Try changing ports, see if that makes any difference. In LW tools > options > advanced > firewall config. Change LW's listening port to 64049 (or try others in the range of 49152 - 65535) > Apply > ok.

If you're determined to download games, always check the file with Bitzi before download. If other users have rated the file, you'll get some idea of it's content & quality. Might save you a few wasted downloads
How to use Bitzi
Remember to always scan downloaded files with your AV before opening them.