Yeah, so the purpose of Web Monetization is not to be another system for active in-app purchases or tipping. It is supposed to be used for streaming of micropayments. Creators should get rewarded automatically and instantly through many many small streams of revenue coming from active use of the content they provide, be it an article, a video or a game.
So think about ways in which you can reward web monetized players as they play your game. One very obvious way is of course to disable ads for a web monetized player. But that is not very integrated into the gameplay experience. How can you tie web monetization to the main game mechanics or meta game? Do they have access to otherwise restricted content? Do they get some kind of bonus? Counters/timers that increase/decrease faster?
(Side-note: Web Monetization itself is based on the Interledger protocol which also can be used for direct payments of any amount)