I guess something I hadn't though of in the "only 5 worlds" concern - and it's not that the worlds could be really big - is that the worlds could each have multiple themes. Like maybe the Temple level has indoor and outdoor parts, and tombs underground, and a cloud realm. Just making random examples here.
5 worlds would feel a lot bigger if each had multiple thematic areas. My reasoning for wanting 6-8+ worlds after all is that I want to see a lot of thematically different content.
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