Pay wall it! You're putting in a lot of effort into the game and I think it's reasonable you want to have your efforts funded. Just leave the current version out as a demo so people can get interested and pay to help out.
Yeah, I don't think 'pulling the rug' as it were with the current version would help any (though maybe?), but future versions will definitely be pay-walled. I already put up the Subscribestar version on here for 4USD, so we'll see if that helps!
