A quick Google for "Joanna Dark N64" reveals some of the detailed pinup renders that were used in promotional artwork at the time. Although quite perky in her own right, I have a feeling she was more geared towards the legs-and-hips set. I mean, seriously... heeled boots and leg plates running the length of her thighs? Not to mention the focus on the angle of her hips, with the leg plates highlighting the skintight dark blue suit...
Even if the in-game model was more of a plain beauty (one that I especially adored in private), the N64 Joanna Dark was as sexualized as any of her contemporary heroines.
No woman is safe from Chicago Ted commercial sexualization.
Even Princess Peach got sexy by proxy with Rosalina, and before that there was Strikers, Tennis, and Melee upskirt...