Thanks for the feedback so far!
The sentry fov is just something that you get a feel for over time...or at least that's how it is for now. If it seems too obtuse, let me know, but it doesn't look like people take too long to get a general idea about how big it is.
For the sentries, their states are three main parts that overlap: Their blinking red light means that they know you're in the room, and indicates that an enemy is more likely to teleport furniture around to try and find you. On top of that, each one individually opens up (and stays open) when they personally spot you for the first time. Since it takes a little bit of time for the transform-into-attack-mode animation to play, the first encounter with each baddie is given a bit of a delay before the shooting starts and becomes a little more forgiving than any repeat offense. Finally, if an enemy has seen you within the last ten seconds, he'll spin around while he moves so he can look for you in all directions at once.
It'll probably take the average player a significant amount of time to fully understand all of these rules, but they ultimately boil down to "don't get seen or shit will suck and you'll have to either get out of there or find a safe hiding spot where you can wait it out." This seems like a pretty intuitive kind of behavior in a stealth/survival setting, so I don't really think that a misunderstanding of the states will cause any serious problems.
That keyboard thing does sound like a problem, though. Might be one of those things that I just can't notice anymore because it's already been janky for so long. I'll look into it!
I've got my normal sound guy
working with me on the game, but his contributions won't be available to the audience until the game is released (I think this'll be a nice surprise for people who've already played the alpha version). He's awesome and the audio will be awesome.
Oh, and I can't use regular alpha fade-outs for the outer walls of the building because it breaks z-sorting, so it had to be something with cutoff alpha instead. I went with stripey bands instead of blobs because it seemed...like...more fun, I dunno. I'm pretty sure that players learn to phase it out really fast. Oh, and I allow the player to leave a wall partially hidden because it allows a very minor extra bit of exploration - if you sit still and look at a partially hidden wall, you can see the bands slowly animating. I'm a total sucker for dumb little shit like this and the game is packed full of it, but I don't have any better explanation for it than that.