I've never heard "creation team". Further, it brings to mind polytheistic pantheons as opposed to groups of programmers and game designers. ;)
You could say "content-creation team" or "creative team", but those are different things, the "content-creation team" filling some large data structure with information (this includes guys who work for Google Maps, journals, writers, poets, journalists, even bloggers could be understood to be content creation), whereas a "creative team" comes up with new ideas.
But, as Joshua Drake noted in the comments on the question, "development team" is a better name, because it describes the whole process, whereas a "creative team" only describes the initial idea-generation, which is a single step in the development process.