[Continuing Gamasutra's 2010 roundup, here are our top 5 PC game selections, including the terrifying Amnesia, the refreshed Civilization V and a certain sci-fi RTS. Previously in our end-of-year round-up: Top 10 Indie Games, Top 5 Developers, Top 5 Trends, Top 5 Major Industry Events, Top 5 Surprises, Top 5 Disappointments, Top 5 Controversies, and Most Anticipated Games Of 2011.] The definition of a "PC game" continued to become cloudier in 2010. Is it a "triple-A" PC-exclusive? Are indie games included? Is it browser-based games? Cloud-based games? Social network gaming? Free-to-play? The beautiful thing about PC gaming is that the answer to everything is a resounding "yes." Just about anything can happen on the ubiquitous and open PC. The only limit is developers' ingenuity and imagination. There's no certification with the platform holder as there is with a console -- the power is solely in the hands of the developer, and that remains PC gaming's biggest advantage. While technically PC gaming does include any game that is played on a PC, Gamasutra is breaking out in separate lists social network games and indie games, which are often played on PC (although there will still be a small amount of overlap with indies). Absent from this list are two of the biggest phenomena on PC this year -- Blizzard's World of Warcraft: Cataclysm, which is an expansion and not a wholly new game, and Markus Persson's Minecraft, which while utterly brilliant and recognized on our indie list, is still technically in beta. Even without those entries, 2010 once again brought the kind of variety that PC is known for, whether its the improved FPS/RPG hybrid Stalker: Call of Pripyat, the terrifying Amnesia: The Dark Descent, the cross-platform sci-fi epic RPG Mass Effect 2, the rebooted and refined Civilization V or the incomparable StarCraft II. Notably, there's only one game on our 2010 list that isn't PC-exclusive, one less than last year. That wasn't a conscious decision -- it really just worked out that way. 5. Stalker: Call of Pripyat (GSC Game World) Having debuted in 2007, GSC Game World's Stalker franchise still possesses one of the more unique experiences in PC gaming. And this year's Stalker: Call of Pripyat, the third entry in the series, impresses with gameplay that feeds into the immersive post-nuclear wasteland called "The Zone." Don't let the RPG-derived questing framework fool you; there's no experience points or leveling. The only way you'll survive mutant attacks in the irradiated Zone surrounding the devastated Chernobyl nuclear power plant is to find the right tools and meet the right people, not by grinding. What Call of Pripyat does best is make the player feel like he is fighting against The Zone and its inhabitants, struggling to survive, but at the same time dependent on its resources and people. Plenty of tense horror-inspired encounters with mutated monsters punctuate players' time in this latest imagining of the franchise, contributing to the players' give-and-take relationship with The Zone. 4. Amnesia: The Dark Descent (Frictional Games) Player dis-empowerment isn't anything new to the survival horror genre, but among big-name video game entries that have a horror slant, whether it's the latest Resident Evil, Dead Space or Fear, there's an arms race that has resulted in protagonists who are armed to the teeth with anything from bazookas to assault rifles and incendiary grenades. In the world of Frictional Games' Amnesia: The Dark Descent you don't have grenade launchers, M16s or shotguns. And even if you did, they probably would be of little use. The gruesome creatures within dreary Brennenburg castle possess a ghost-like, ever-present supernatural-ness that makes them terrifying, as if they can appear at will in order to menace protagonist Daniel. A Raccoon City S.T.A.R.S. member would likely wind up a sobbing mess in a corner somewhere deep within Brennenburg. It's not just the creatures, but the castle itself that has the ability to petrify players, with immersive, eerie sounds and environments that, even with no enemies in sight, often bear down so hard on players that they have to step back and collect their own sanity to remind themselves that this is only a game. 3. Mass Effect 2 (BioWare) While designed with the console player and controller in mind, BioWare did a commendable job of bringing the action-oriented role-playing game Mass Effect 2 to PC players. A sprawling universe, unexpected, clever story developments and a memorable ending (much more so than the original Mass Effect) means this RPG finds fans on both sides of the PC-console divide. There are some legitimate complaints about the game: the battle system, while improved, could still do with more interesting inter-character combo attacks, the side roads of a branching storyline ultimately merge back into a largely linear interstate, and, well, there was the planet scanning (which wasn't quite as tedious with a mouse as opposed to a controller). But even with those concerns, Mass Effect 2 is overall an experience infused with memorable characters, planets and events that feel distinctly "Mass Effect," a notable achievement in such a crowded genre. 2. Civilization V (Firaxis) It's somewhat ironic that Take-Two developer Firaxis delivered such a thorough re-freshening of the classic Civilization franchise by employing a decades-old strategy game concept: the hex map. Civilization V is the first time that the franchise has used a hex map, but the changes and improvements to the series went far beyond that fundamental shift. As a whole, Firaxis managed to accomplish a supremely difficult task, which is streamlining a complex strategy game to make it more accessible without dumbing it down. It launched with some issues -- particularly with the A.I. -- that Firaxis is sorting out with patches. But for most players, even on release day, Civilization V was still was fun enough to play for hours straight. To call this game a timesink is a disservice; Civilization V solidifies the continuing relevance of the revered series, and is one of the best arguments for the relevance of the overall turn-based strategy genre that you can find. 1. StarCraft II (Blizzard Entertainment) Some have derided StarCraft II as an antiquated click-fest; a remnant of resource-gathering real-time strategy gameplay that came to prominence -- and should have stayed -- in the 1990s. Perhaps some fans of StarCraft II would like to argue that such naysayers are completely wrong, but actually, detractors have a bit of a point. If you want huge innovation in an RTS game, don't look to StarCraft II. But if you want fast-paced multiplayer gameplay that has over a decade of polish under its belt (plus continuing balancing) and a single-player story that delivers the flawlessly-delivered, borderline sci-fi camp-ness and action that StarCraft fans expect, then here's your game. Innovation was never Blizzard's goal with StarCraft II -- the goal was peerless execution. Just the fact that the incredibly-polished StarCraft II delivered on such inordinately high expectations is enough for it to make the top of this list. Successfully take on the enormously difficult task of integrating the game with a totally new Battle.net, sell a million copies on opening day and bring back old StarCraft fans while creating new ones... then you have the standout PC game of 2010. Honorable Mentions ArmA 2 (Bohemia Interactive) Supreme Commander 2 (Gas Powered Games) Call of Duty: Black Ops (Treyarch) Fallout: New Vegas (Obsidian) RUSE (Eugen Systems) Super Meat Boy (Team Meat) Bejeweled 3 (PopCap) Battlefield: Bad Company 2 (EA DICE) DeathSpank (Hothead Games)