Most people on the other sites probably visit this one too occasionally. It's already been posted as a news item at
amigans.net (with a link to your thread here). There's also
amigaworld.net which is more geared toward Amiga OS 4.0, but there'll still be people interested in starfighter.
You could also try
morphzone.org. It's about Morphos, not Amiga OS, but it's an Amiga OS 3.x compatible OS, so they're also Amiga enthusiasts. Finally, there's
aros-exec.org for AROS, which is also based on the Amiga OS API (but not binary compatible).
I can't think of any other places.
Hans