Aha, yes! I've done some H1 checking on Heroic and there's a timeout thing going on. Basically if you wait long enough the game will kill off any remaining covies from the airlock group, and Cortana will deliver her lifeboat prompt. After that, the cutscene will trigger in about a minute even if you're nowhere near the lifeboat. As such, it's actually possible to get off the ship without killing a single one of those final covies or approaching the lifeboat door!

By the way, how come you crouched hidden for so long? I mean, there were only a couple of Grunts left to kill.

: Might see if I can't work some more of this kind of thing in a future part.

Just to add a thought to what I was saying, you added your voicing after doing the gameplay, right? So, you knew you weren't going to die, and I suspect that's why you sounded so casual when you were twice on the verge of death. So I'd say this was just a little slip in matching the acting to the moment.

: I do this totally subconsciously now!

There are times when I deliberately move in closer to an Elite so he'll take a swing - because that stops him firing for a moment and also leaves him open to being finished off in various ways.

: Totally didn't occur to me, unfortunately!

I'm amazed you could forget about it. That grenade rack is such a gift! Kind of like the level's reward for getting that far.

: Was there anything you think I could do to improve series 2? You know my limitations.

One thing I'd like is more attention to continuity where possible; so perhaps it's time to start thinking about exploiting checkpoints to manage that, as long as it doesn't compromise comedy structure too much. In this series there was quite a discontinuity with the stairs fight. Not just the Sergeant Avery Stacker debacle (maybe you can explain that away when you next meet up with Johnson?), but also there were originally some covies still alive up top, who subsequently weren't there, so I felt a bit robbed of a full fight. Aside from continuity though, and the audio limitations you're stuck with, I think things are structurally pretty solid.

The only other generality that comes to mind is, it might be worth thinking ahead through the level to plan out certain things (if only loosely), with a view towards maximizing opportunities for comedy and incident, and keeping things varied. But maybe you've already got this in mind, I don't know.

When it comes to specifics I'm sure you've got plenty of ideas. But if you want another (if you didn't think of it), perhaps this picture of two Johnsons will suggest some comedy potential to you (click it to enlarge). Could make a memorable feature/theme! For that matter, scanning through my site pics might give you some other ideas or inspiration, if you ever think you need any. Feel free to borrow!

: I see this series as kind of a pilot for my self and am
: thinking of changing a fair few things for future parts.

Changes huh? I wonder what those could be.