Many games are wrongly configured and do not seem to run. Games usually run best with KS1.3 on an expanded A500 (1MB), while later games with AGA, need to run on KS3.0 and an A1200 with 2MB+. it seems that many are configured to run on a KS2.04 A500.
BTW, they use the Scripted Amiga Emulator: http://scriptedamigaemulator.net/
Note: reach out to me... would really like to help with improving this.