What really doesn't make sense is this.
The scientists are working on a portal, right? We all see the portal in the game. It's where all the monsters come from, right?
So, if they are all arriving on the base at the location of the portal, how in the hell did the monsters acquire the ability to teleport to any location in the base after they arrived at the portal?
I mean, it would make sense that they all entered our world through the area in Delta Labs, which is where WE, the game player, go to Hell, right? That seems to be the place where the teleporting is occuring.
So, once teleported to the Mars base, how do the monsters then become able to teleport themselves to pretty much any location on the base, ie right in front of you, behind you, etc. It makes no sense at all.
I mean, if the monsters can teleport all by themselves, then they didn't even need the Mars scientists to make a portal then, right?
The rift in the space-time continuum and Captain Picard said, "Make it so," and Scottie teleported behind and said "Look cap'n I canna make it so, I'm surrounded by a bunch of daft thingies."
It's the rift and the energy from the rift that allows them to teleport where they wish. Consider it a benefit of our dimensional travel curve being bent by their's. I believe Heisenberg accounts for it.
As for the flashlight...I doubt even Einstein could figure that one out. But you know...maybe they only have perpetual motion machines for batteries that suck power from the vacuum (and give the flashlight infinite power) but they interfere with their firearms.
You know...the Spit or Swallow Theorem of Relational Bullcrap.