Yes, rendering flat sprites in a 3D space is a bit of a pain at times, and yet, while the current implementation works just fine, it's a bit odd for certain things. For a good example of this, try firing the plasma gun straight up in the air. Notice how the projectiles look very flat in this way? For monsters and pickups and the like, this rendering behavior makes sense, but for projectiles it's a little odd. Most of them are spherical anyway, so shouldn't the bottom look the same as the side, anyway?
A quick image example, for clarity and confusion:
To sum it up, perhaps a special flag could be added that tells the renderer not to skew the sprites and always view them from the front, assuming that makes sense? I recall JDoom posessing a similar ability (albeit as a useless user option), and it would make much more sense from a visual perspective.
