Airline Club

Instead of relying on patreon, why not try getting some ads added to the game? Nobody likes ads, but it's an easy way to secure some additional revenue, and in the end, it's really not a big deal on the user end. Every 1000 clicks is a few bucks on average, so you'd need to look over your site traffic to see if that's even viable in the first place though.

Large empty spaces, could fit an ad or two in it if Patreon doesn't work out or doesn't get enough money.
Maybe make donating to the Patreon remove the ads for you aswell.

Get it from both sides, nice idea. I can already see a few empty spots that ads would fit pretty nicely in