What other cool stuff is there?

Hint 1 of 5:

(1) At the beginning, turn around, and check out your ship for an RPG.

Hint 2 of 5:

(2) Where you find the switch to open the first door, there's a room behind
the broken monitor screens.

Hint 3 of 5:

(3) Check in the dark room that you find the blue card in for a vent that
leads to some interesting places.

Hint 4 of 5:

(4) Look around the domed area for a jetpack on a ledge.

Hint 5 of 5:

(5) In the corridor right before the red key card slot, duck in the light and
press space.  There's a hidden area down there.