: And Mark really missed one - a chip is required to access that
: airlock. The chip is in the center of the levl, right where the turtles
: are.
That chip is dropped by one of the Turtles. One of them is minor and the other major. The minor one drops the chip. But it's actually not needed to access the airlock. The "chip insertion" switch on the left is really just a tag switch in disguise. If you ignore the chip, you can still get through the airlock. Perhaps Ian realized how low on oxygen the player would be at this point. I'm guessing he changed the chip insertion switch to a simple Tag switch without changing it's look. That way the player doesn't have to defeat the Turtle. And on Death Wish, defeating the Turtles is definitely not easy. On the other hand, perhaps it was purposely done so that the player wastes time trying to defeat the enemies for a chip.
Also, on this level you have only your Pulse Rifle available. That weapon does not seem to provide any lift to launch the player onto the ledge containing the oxygen canister, despite this also being a low gravity level.