Two of our own store links were pointing at nothing
While building the game pages we checked every store link against the actual stores rather than against our own records. Two did not survive that.
Rollerball Arcade was listed internally as live on both stores. It is live on Google Play only. 52 Pickup was listed the same way and is live on the App Store only. Both games carry a cross-promotion screen that reads from those records, which means for some time each has been offering players a link to the other that goes nowhere.
It is a small bug with a disproportionate cost — a dead link inside a shipped game is the kind of thing that quietly teaches people not to trust the next one. The site is now correct, and there is a script that re-checks it against the live stores so it cannot drift again silently.