A pun on Waluigi's name counts even if the name Waluigi isn't spelled out. For instance, if Nintendo released a game called Door Mario and Wall Luigi, that would count.

Minigames don't count, the release must be purchasable or obtainable separately.

If there's an app that's not technically a game for the Switch 2 or IOS like Waluigi's Weather Channel or whatever, I'll count that as YES. But a Waluigi theme park ride doesn't count.