Good stuff. This is where I got totally pissed off with the game for long boring level design. Assault on the Control Tower was bad enough - on and on and on, another bridge, another octagonal room, another downward corridor, another octagonal room, another bridge, an outdoor area, a cave, another outdoor area, an octagonal room, a downward corridor, an octagonal room, ad nauseum ... but then running it backwards? Thankfully by then my intelligence circuits had melted, and I didn't even notice, except for that tower with the invis and health you mentioned.
Having not paid attention, I raged after waltzing into the second power generator thing and finding out there was still another one. As if it hadn't taken long enough.
Also really wasn't a fan of the multi-level maze design of 343 ... which also, really, still a name I just can't warm to. And these conventions carried on through to Destiny much the same, to the point of this: http://www.polygon.com/2015/1/16/7559177/quiz-destiny-gun-or-swedish-metal-band
At least Marathon used Latin to cover up their ridiculous names.
The flood spawn things are a lot of fun with a shotgun, as are the flood zombies and such, and so nice to have such a big clip in the shotgun! But the irony becomes that it takes ages to reload, although we can interrupt it, and we can't dual wield it, lol ... not even when Halo 2 brings back the very concept of dual wielding, strangely lost to Bungie between '96 and '01.
