This could be a really cool time save.

This is for the mission research lab on the Predator. This was discovered by someone on a discord server. (Shout out to DreaM TeaM on YT for finding this.) At the beginning of the mission, you run along the normal path until you hit the first building. You walk up the stairs and jump over the hand rail, lining yourself up in the center of the wall next to the walk way above your head. All you need to do is hold W (or forward on the joystick for the controller) and you will begin to walk up the wall. You need to go high enough up so you can fall down onto the walkway above. Once you do that, you head through the door and go through the other door that will bring you out into a hallway with a big glass window. (There will be invisible objects that aren't loaded that will get in your way. All you need to do is jump over them.) Pass through the left door, then jump over the hand rail on the right side to land on the walkway below. Take the path on the right side all the way around to the egg chamber. This will load in the elevator needed to end the mission. Run back over to the button to call up the elevator. As soon as you hit the button, this will turn off your cloak. Make sure to instantly reactivate it as there will be 4 enemies on another lift in front of you that comes up. Wait for the elevator you called, and once it gets to you, just walk onto it and hit the button on the other side to end the mission. I will link DreaM TeaM's video down below to show how to do the level.

For the past couple of days, I've been trying to practice Corpseflesh's rooftop skip for the Marine mission Refinery. For it to work, you need to hit it at a specific angle. The best way I've found to go about it is that you want to be just to the left of the gap in the barbed wire. As you're walking up it, you need to swing left, then come back in towards the right a bit. After you turn back right, you need to jump. If you angle yourself a little too far to the left or right when you jump, you will hit the death barrier and die instantly. It's tricky to do, but if you get decent at it, I think it could become pretty consistent. I'm going to include a video to show it off, so if anyone wants to try it, they can use it as a reference.

Found an area where you can skip over the trash in the mission Colony. I can't get it consistently. I'm trying to currently figure out a way to get it more consistently. The only way I've been able to do it is spinning my camera towards the right as I'm jumping, but I figure there's got to be a better way. If anyone wants to help in figuring out a more consistent way of doing it then have at it. I'm going to keep messing with it to see what I can find. Short video is included down below.