Afaik there is no way to verify purchases (since Apple never sends you a receipt for it). It's trivial to verify in-app purchase receipts server-side, however.

Afaik there is no way to verify purchases (since Apple never sends you a receipt for it). It's trivial to verify in-app purchase receipts server-side, however. And that could be used to allow (or not) access to the multiplayer bits.