Level 4: Second Floor
You will have to find another elevator and see if you can use it. On this floor, you must navigate a maze of offices to find a way into the back rooms.
Several
items in this level can only be reached when you fall from atop the cubicle
borders. Only one of these items - the green key - is vital, but the other
items include your first plasma gun and the items in this picture.
This
switch, built into the file cabinet, lowers a certain platform. The picture
next to the switch will give you a clue as to what happened. Also, the
broken monitor sprite is shown here.
After
entering the red door, you'll be able to teleport up here. This catwalking
process is necessary in getting many items in this level (see first screenshot
on this page).