I've finished it, in all its creepy glory. I still get the shivers with the damn dark dankness.
A few annoying things, and quite a few great ones to add to my other points:
I don't fully agree there are big plot holes. Listening to the Radio's are very interesting. Fontaine aka Atlas (sadly, I saw a note on this before I got to that section, it wasn't something I didn't fully see coming however once I got nearer to Ryan, was a bit obvious something was up...) really put on the act, and although it is not explained fully why he was there in person at the sub, it gives your character more motivation to go down to the sub. I thought "Would you kindly..." was excellent, and I was always wary of Atlas - the objectives seemed pretty pointless for me to do compared to asking questions and doing what I liked, but that made it have *some* kind of sense at least.
I am surprised Ryan didn't figure out Atlas was Fontaine and took his fate so badly. He basically lost his city and protection his inner chamber gave him, so he shut down the security, and committed suicide (Quite possibly turning off the chambers first, obviously). Quite touching, he was a great character and personality. A man who had a way with words wouldn't be a good character to have a "boss fight" with. I am glad he was the main "adversary" for most of the game. He built his city, and it fell apart due to Fontaine and the creation of ADAM.
The gameplay got highly repetitive, although playing on hard was quite fun, since almost every enemy (even after research, which was a nice touch) was a challenge. I kept getting too much stuff, so I obviously was exploring enough at least.
Well paced game, although not exactly exciting objectives most of the time, at least it was something to do - the Mall and the "Masterpiece" work was quite fun, if very creepy...
The ending though, was entirely a letdown, the last boss was pretty boring (I am surprised it didn't have things to hack, hordes of splicers and security, or anything. Also it'd have been cooler if being a Big Daddy allowed you to equip the drill...
) I don't
care that it could be expansion or sequel material, but both the good, evil and mostly evil endings were very short, and didn't show what happened to Rapture itself, Tenenbaum, the other (thousands of?) Splicers, or Ryan and Fontaine's bodies. If anyone is interested, the main difference between the "nearly evil" and "evil" endings are that in one it is implied you kill all the little sisters ("evil" ending) and the other it is just implied you take the city. At least the good ending made some sense and was pretty touching, if very short and missing the above things.
I also hoped for a few more moralistic choices other then the little sisters. It's obvious that most of the splicers are unsaveable, but there would be at least some that were not totally mad, right? Law of averages?