I know, I know...
But what if some things were changed just a little to make Tremulous a little more realistic? Now I'm not talking about better physics (although that would be nice) or anything that would be difficult to change, just some things that might cause Tremulous-related dreams to be more nightmarish and not having ponies and fuzzy bunnies hopping in fields of poppies (I think I have a script for a movie...).
The stamina is screwed up. You can sprint to the end of the map and back and be barely out of stamina, but you can't jump 4 times in a row. This might make a little bit of sense on maps with high gravity and really low air pressure (though, that would make breathing harder, shortening your sprint time even more). Can this be upgraded to maybe 10 jumps?
Aliens should have stamina. It should effect most classes almost never since most classes can't sprint. But a tyrant can charge... and keep going... and charge again... In reality, large animals that can go really fast can only do so for a short amount of time (the current charge is fine), and exert themselves pretty quickly and have to stop or slow down.
Gravity doesn't effect aliens? You'd think a tyrant falling 30 stories should at least stub its toe. But it barely hurts a normal granger. And yet a human dies instantly.
It takes a damn long time to kill teammates at point blank range into their heads. Maybe we shouldn't encourage team killing, but a stray bullet from an SMG entering a teammates brain should kill or disable him 98% of the time. And a few shotgun pellets to the back should at least take away some of his stamina. (The way to do this would be either increasing damage done only to teammates or increasing the damage of all of the weapons and increasing alien health.)
Anything else?