Ask HN: Where is it acceptable to advertise a beta mobile game?

I just finished the MVP of Community Chess (www.AngryElement.com) and I'm trying to figure out how to get beta testers. I've thought of posting to /r/playmygame but it doesn't appear to be for betas and certainly not for closed betas. I thought of doing a "Show HN" but that's also not for doing beta signups. I currently have 30 people who are ready to test but they are work friends and family members so I'm worried about their bias. Thanks for any advice you can give. I'd also love to get some tips/tricks on how to improve my website.