: Dammit! So those small rooms on the maps are significant, rather than
: the likes of M2's test rooms. I already realised i missed one with a
: terminal on Sensori OverLord, but will have to generally pay more
: attention to the walk through, assuming that is where you found out this
: one :)
No actually, I think I found it on my own quite a while back. I think I was looking for a way onto "You, that's who!" (not realizing that the actual entrance to that level was on "Hostage"), and I came across those secret switches. I started looking around on the map editor to figure out how those worked, and somehow I figured it out. In future, though, I think I will be making good use of the spoiler guide.