There are certainly contrary opinions about the MacHeist sales approach (at least among indie developers), but they are legit. I've loved lots of Pangea's games over the years, so Enigmo 2 is especially welcome.
do these work with powerpc... or like everything else no?
Enigmo 2 is universal binary, so assuming you are running 10.3.9 or later you should be good, I am not to sure about the rest, but it is safe to assume universal binary at the least.