Part 3 in progress.

@Swiss-Army Swaus - Noted, thanks for your feedback. I'm making some unique changes in the next week so this is something I will look at. If you are referring to the one before you jump down the airshaft, that one exists for easter egg purposes, whereas folks can find another red keycard just after they go down the stairs, past the mutant enemies.

Could you have put the red keycard in an area you couldn't accidentally miss? Players whom go down the airshaft have no way of getting it. Putting it in a room with no enemies would be preferable because the blood and action can conceal it. (I found the card, but wasn't impressed by the location.)

Sorry to hear you're having trouble - there's two locations to find them, and you will slap yourself silly when you see it. :-)

The first one will reveal the Easter Egg portion of the level and the second is part of the main level, after the staircase section.

Can't seem to find the red key card, killed everyone and ran into three doors I can't open