Yes, that's right. If I remember correctly, I laid out the whole dungeon with D&D dungeon tiles and then ran it for my kids. I knew what was in each room, but they didn't (the conceit was that their characters had a map). Because SOBH is such a dynamic game, it led to lots of racing around along corridors, with portcullises being dropped and people ducking behind doorways and so on.
The key thing to remember when doing this, I reckon, is the Ambush rule in SOBH - you get +1 to shoot or fight if your opponent couldn't see you at the start of your activation. So it's an incentive to go for three activations (two to turn a corner, one to shoot or fight) - although you can sometimes exploit it with two in a dungeon environment (moving through a doorway into a corridor and shooting, for example).