Hello Harry,
Well I downloaded your game and thought I'd give you a FULL review. (this level deserves one) First off the load time was a little long, but over all not to bad. Though you might add some music in place of that horrible stock wav file, I really think it makes the load time's seem soooo... much longer then it really is. Anyway, on to the game.
I must say you have a very keen eye for detail and great placement ability. Right from the start I felt drawn in to this level, everything just clicked.
The beginning of the level flowed evenly and I didn't notice much hesitation in my movement. The placement of the weapon was good and felt right. The first enemy had good movement and attacked well. Though I would rather have started off with 100 health. (this would have made the longer range fight a bit more intense IMHO)
Moving on to the second enemy, I really liked his placement as it lead to great movement on his part, but I did have a run in with a third enemy. I'm thinking he was in the room on the left before you get to the first tank (with the steam and barrel)
I'm not sure if this was intentional or not but I never saw him, just took a hit or two then I turned to watch a pistol slowly side into the wall. (did you by chance place him behind the door?)
Continuing on to the stairwell I noticed very little hesitation even though you had enemies and had a pretty good amount of open area.
The only place I found some hesitation came in the next section, which I admit was still very playable. The area was large yet everything fit well together, the layout was proportioned very well. (meaning that the room felt even and full, but gave plenty of room for movment)
Here is where I came across your "Invisible enemy" yet again this time after I thought I had cleared the area. I was exiting the upper most room, when I saw a pistol gentle floating in front of me at the "T" section of the gangway, that I'm sure was not there when I came past before. As I approached to gather what I thought was ammo I took a hit for health, after shooting the unseen enemy I got a quick view of the Thug model.
I also found another at the bottom of the stairs. Again same thing floating pistol held by a invisible thug model, neither of which fought back or even moved from thier place. Again I'm not sure if this was intentional, but it added a creepy element that's for sure. (by my count there were 6 enemies in this area; 4 seen and 2 unseen, Though I did hear another walking around the medical/lab areas that I could not locate)
As for the rest, right back to good flow and little if any hesitation or stutter. Over all I'd say; if this is how your going to make a complete game, with the great placement, the easy flow of the map, the nice balance of space and your eye for detail. Then you'll definitely have a winner in my book.
Regards
Mark
If not for physics and law enforcement, I'd be unstoppable!