There never really have been official OST's for the vast majority of Nintendo's software. Back in the mid-to-late '90s, they dabbled a little with in-house releases of OST's for such games as the DKC series, Mario 64, Mario Kart 64, Diddy Kong Racing, Yoshi's Story, both N64 Zelda titles, Perfect Dark, Paper Mario, and a couple others, but it still amounts to a drop in the bucket.