Topic on PCGamingWiki talk:Taxonomy
I think it would make sense to specify both primary genres and secondary genres when specifying genres a game. For example, Sonic Adventure DX is primarily a platformer and action game, but there are also two pinball tables in the game. These are only in one stage, so it doesn't quite make sense to list pinball with the more pertinent genres. Of course, this gives some ambiguity: is SADX also a fishing game because that is the gameplay of one character (ditto for shooting)?