Thread:Quakeman1/@comment-3547390-20150711112610/@comment-1496755-20150714150428

For the sake of accuracy, I think Descent predates Quake as the first fully-3D game. The only sprites in it were the item pickups and the explosions (Quake's explosions are sprites too). Also, it has unrestricted 360-degress movement.

Yet, Descent's engine had numerous limitations that don't exist in Quake - the most significant of them being confined spaces (basically, the engine can only render indoor environments with properly defined self-contained rooms). This doesn't mean that the game doesn't feature some pretty creative (and beautiful) level architectture, yet the limitations are certainly felt (especially when comparing to Quake).