Have you tried Facebook Marketing yet? It's roughly $15 for 1 week of advertising (maybe for two weeks, can't remember at the moment).
You can also try submitting your game to GoG for free but they will play it and judge it worthy or unworthy. For $100 you can upload to Steam and they give it back if you make $1,000 or more in sales. Having your game on either of those marketplaces is like it's own form of passive marketing.
Hi ArtofKings,
Greetings from Traveloka! Hope this mail finds you well.
I’m William, Business Development Manager from one of Lifestyle apps in South East Asia Region, Indonesia origin.
Currently we are exploring Partnership with various Gaming companies, it is very exciting to think of the idea where we could on-board games made by you on our platform. The idea behind is to provide wider things-to-do options to be offered to our customers and at the same time help Play.co to distribute your games to our unique SEA base customers.
If you are keen we can set a call.