Since I think using ads on most social media is currently difficult, I suggest:
- Posting a thread about your game here on bitcointalk(and make it a good one, not a text-only thread without enough details)
- Paying a crypto-related website to place a banner of your game up on their site
- Advertise through crypto-related ad networks like coinzilla etc(not affiliated with coinzilla)
- Advertise here on bitcointalk [1]
- Probably a signature campaign?
[1]
https://bitcointalk.org/adrotate.php?adinfo