This seems quite interesting. Although unfortunately I haven't been able to make it work
I have tried by dragging the executable file of the game, or the .dat if it is not in an executable format and it doesn't work. I tried various, but I always seem to get the same error:
Adventure Game Studio for Mac
Invalid file format. The file may be corrupt, or from a different
version of AGS.
This engine can only run games made with AGS v2.5 or later.
Changing topic a bit, people have mentioned the use of virtualpc (powerpc) or parallels (intel) to run AGS or its editor. However, I've been using crossover for mac (which is basically a commercial version of wine) and both the editor and engine work perfectly! Of course, Crossover has two problems; it is not free (about £30 for the license) and it only works on Intel Macs. However, the first problem has a soution: you can use Darwine which is a free implementation of wine for macs (Haven't tried it myself). It should work, although it is arguably more work than crossover...
Regards, Nahuel, Good luck
PS: I screenshot of my using AGS Editor on my mac: