Hi, not sure if you want to simply have the possibility to pay in btc or if you want to include the transactions on a chain (which means you can save the goods you sell in the game directly on the chain, and these good will become "property" of the users).

In this case, maybe you can migrate to an ethereum (or other smart contract like system) smart contract. In case you use eth, you can query the eth chain in app via web3 and infura (or set up a web3 server yourself).

If instead you want to use btc, as other say, you have to setup a payment service by your own (very risky) or pay an external one. Also keep in mind it will be slow and at risk of high fees (unless you use LN).

The article is interesting, but to my point of view it is like writing:
Internet is e-mails, and there already exists a perfectly working mailing system. And, if you want to send a physical good, you cannot do it. So, the old mail system will live forever and internet will die.

Of course, the truth is that both, e-mails AND old post system still exists, because they address different needs. AND, internet has evolved in offering a set of services which where unimagined at his creation.

And this ways of use are still waiting to come, we just need time and adoption.

But Stinchcombe is right, the blockchain will not improve the things that perfectly works with a centralized approach. Indeed, it will create a huge amunt of new markets and services which are, now, in anyone's mind.