That's an intriguing question! The game and the case aren't eligible. But a manual might be. Books are eligible if they have 8 pages, and are bound, IF they don't have advertising (except for other BOOKS). There's a rule that says that if an ineligible item is included with an eligible item, then the whole package is ineligible.
So if your package is inspected, even IF the manual is eligible, it could get disqualified due to the case. IMHO you shouldn't take a chance. Remember if it's under 1 pound you can ship via First Class for not much more than MM.
