New things added since the last update.
Teleporters – Can transport players, monsters, and even weapon projectiles
Monster Portal – spawns new monsters non stop till it is destroyed.
Secondary weapon – grenade
Default mouse cursor
Team support for future game modes like, deathmatch, capture the flag, etc.
Splash damage
Explosion sound to rocket explosion
Infinite Ammo cheat
Muzzle flash to gat turret
Friendly Fire
Also a bunch of improvements to multiplayer support and may include it in a future demo.