If you mean the developers (Snowblind Studios), they were absorbed by Monolith and are no more. If you mean the publishers (Warner Bros), well, they don't seem to be going anywhere for the time being.

Unfortunately it still exists, and Bulletstorm was not one of the lucky games to have it removed.

After going through your steam list I have this recommendation:

Install the games your have and try them instead. You have 644 games on Steam alone and only 261 have been played at least 0.1 hours, barely 40 games played above 10 hours.

Dark Souls. Do yourself a favor if you have a controller.

Dark Souls
Dead Space
Alpha Protocol

There is no non-steam version. With DSFix the game works fine. Even good. The native state of the port is garbage though.

I wasn't sure if Steam only or not. I had it on xbox 360 a while back. Never got to beat it but had a good time when I had it before my xbox gave out on me.

I'll keep an eye on Space Marine as well. You are right that I don't much care for RTSes, so I'll see with that :D.
Also, if the first Darkness is better, surely I should aim for that? I'm not too fond of horror games either, though...they seem to oscillate between jump scares (which just irritate me), and boring overdone blood-stained wall stuff. I played Amnesia for a bit before getting somewhat bored of it as well.

As I said, I'm not REALLY one for RTSes. The fellow who said that had it something like Civ V with the expansions, Civ 2, Civ 3 and then Civ V without expansions.
I watch Yahtzee's stuff mostly for comedy, but his opinions very often do happen to match my own, which is why I follow them. Still, I'll keep an eye on Castlevania, since you say.

The list is a bit of a confuser in that regard :D. The vast majority of the games in my Steam list are Humble Bundle games I played without Steam, or free to play stuff that got added there, or games that I've played before I got them on Steam, or in the case of distastefully DRMed stuff, things I got annoyed with the DRM of, so I downloaded "elsewhere" and played it DRM-free (something I suppose I'd rather not do if I don't have to). Most things that I played for less than an hour or two is stuff that probably didn't stick to me, so I uninstalled them.
There is of course loads and loads of stuff I haven't tried and much that in fact I want to get to, possibly almost half of the remaining list (and that's not even counting the Dragon Age freebie and Humble Origin Bundle stuff I have on Origin but have never tried). But I'd still like to keep my eye out for good deals on good games I may not know about!

I've been recommended Dark Souls before, but I don't have a controller, and I'd prefer not having to get one...I like my PC gaming with the keyboard and mouse, even stuff like Darsiders and fighting games and such.

Also, I'm even more confused about Assassin's Creed than before :D. I had heard that Brotherhood was mostly multiplayer focused, and I'm the absolute exact opposite of multiplayer focused... I know lots of people prefer to go in sequence for the story and not to miss out stuff, but I like to think most games are self-contained units...so disregarding that as an issue (but certainly not overall story quality of the individual game)...what should I look out for? 2? Brotherhood? 3? 4? Black Flags? Not that it really matters, I guess, with the uplay stuff.

Get Assassins creed3!!!

Civilization isn't an RTS- even including its spinoffs, it's all turn-based (Call to Power, Colonization, Civ Revolution, Alpha Centauri, and After Earth). Do you perhaps mean you're not a fan of strategy games in general? Or did you misread the part where someone was asking me if it was similar to Age of Empires, which IS an RTS?

Sorry if I caused confusion earlier lol.

You are right, of course. These genre names are a bit confusing. I'm sure everyone GETS what is meant when I speak of games like Civ and Colonization (actually one of the very few "strategy" games I care for, but that's probably nostalgia), and Age of Empires and Warcraft 1 and 2, and so on, but if I click the "Strategy" category here or on Steam, I get games like FTL, The Incredible Machine, Spacechem, Divinity games, Battlechess and This War of Mine, which isn't what I mean at all.

Do yourself a big favor and get Metal Gear Rising. It's made by one of the best studios in existence: Platinum Games.

Then once you become a fan of Platinum (you will) join us in our eternal battle with SEGA to get Bayonetta and Vanquish on PC! (We already got hints it's working!)

There is that Square-Enix sale going on, and I wonder what, if any, games I should get from it. Either that, or hold out and hope that someday Team America finally brings it's crap over here.