Posted by: Penguin Egg
I can name a few big skips here, there are speedruns on yt though. You can skip the whole first part without killing anything until the buggers, taking like no damage. Theres a hunter skip, basically despawning the hunters so you dont have to deal with them, and if you have a concussion rifle + tilt skull, you can kill 2/3 dropships at the very end of the level using the mac gun (concussion rifle jump to the gun the same way you would go to get the unfrig medal) . The only parts that are unskippable are the buggers in the canyons and the final room.
Ah, that does make it easier, playing it without skipping anything was kinda hard though.