Deus Ex, if you ignore that it really is ugly as sin. Sounds amazing! Plays beautifully! But yeesh, Unreal Engine 1 humans.

Most immersive sims are arguably in the same boat. The people involved had enormous ideas. As commercial products, they were woefully underappreciated, until years later. And quite frankly they do look like shit compared to much simpler contemporaries. Some NoClip documentary about Looking Glass could show a major artist had muscular dystrophy that makes his shoulders work wrong, and I'd be like, oh, that explains things.