BUGS IN THE WALLS
There are bad days, and there are days when you're just screwed. 
In case you had any doubts, this is one of the latter.
 
 
AIR DUCTS
=========
Filling in for almost any kind of narrow passages, the air ducts 
can be used by the enemy to move around the sector. You can see 
and shoot into the ducts, but your soldiers' armour is far too 
large to fit inside them. 
 
This means that wherever the ducts are present, the enemy will 
easily be able to outmanoeuvre you - watch out!
 
 
SECURITY DOORS
==============
Unlike the regular doors which can be opened and closed by both
your troops and the enemy, Security Doors contain a sophisticated
lock which only your soldiers are able to operate.
 
Security doors are marked with red colour in the overhead 
display, rather than the yellow the normal doors are marked with.
.
