This mod allows system link co-op in halo 1. The bsp switching is fine if your near your team mate. The reason you see less enemies is because halo’s netcode can’t handle all that data, as it was only meant for multiplayer. This NOT possible for PC, sorry.
Assassination on the Halo Reach level Swordbase
An amusing shot of an elite with lightning bolts coming out of his hand.
Halo 1 Beta Xbox Grunt Pillar of Autumn
Halo 2 Beta, Zanzibar chief assault.
Halo 2 Beta, Ivory Tower.