There's no such thing as "Oceania". The biodiversity of Australia and New Zealand is vastly different; the cassowary and emu represent Australia, not "Oceania".
I tend to lump Australia and the nearby islands in my head while trying think of regions that are lacking.
This is what I mean:
https://en.wikipedia.org/wiki/Oceania
There aren't many land mammals to pick from on many of the islands, but there are many cool birds. The Kiwi seems essential for New Zealand representation, but I don't think there is much else besides penguins (some of which also range in Australia), maybe a fur seal, and a sea turtle that have a chance to end up in a habitat. Maybe a Nene goose??
I think the little blue penguin would be a great addition, but I mostly hear about it in the context of Oceania rep, which is lacking. Most of the Oceanian animals in demand are from Australia, but there are also a few from New Guinea. The kiwi is among the top five birds I would add to the game and is the second most requested habitat bird. The others of my top 5 are: scarlet ibis or roseate spoonbill for SA, Mute Swan for Europe, Grey Crowned Crane or Secretary Bird, and the Mandarin Duck.
I meant no disrespect to New Zealand and other Pacific Islands. What beyond the Kiwi would you recommend for habitat animals?