Two things from the page rather than the build, neither already mentioned here.
Your page looks like it has no cover image. I grepped cinder-box for og:image plus three other itch game pages as controls: the three controls emit one, yours emits none. That matters more than it sounds, because itch's Getting Indexed doc lists "You have a cover image uploaded on your page" as a baseline requirement for being indexed - and "cinderbox" does not come back from itch search at all, four days after publishing. Searching your project's full title is itch's own stated test for whether a page is indexed. If that reading is right, the mobile-scale fix is landing on a page browse cannot reach yet.
Second: no tags and no genre. Your info panel runs Updated / Published / Status / Platforms / Author and stops; the two other pages I pulled this morning both carry a Tags row between Author and the rest. Tag pages are a real browse surface - they are measurably one of mine.