The Zone isn't a friendly place, and if you played last year's shooter/horror/role-playing hybrid S.T.A.L.K.E.R.: Shadow of Chernobyl, this comes as no shock. Clear Sky offers a few improvements and a number of issues, but the real star of the series--the large, barren wasteland created by a fictional explosion of the infamous nuclear facility in Chernobyl, Ukraine--is still the most impressive aspect of this prequel. This isn't a full-fledged follow-up, but rather a stand-alone expansion set before the events of the original. You're introduced to a new main character and several new mechanics, the most important of which is factional gameplay, which allows you to ally with an AI-controlled group and assault its enemies. Unfortunately, new features come with a price: new bugs, erratic difficulty, and other annoyances further disrupt the immersion. While Clear Sky is a good game, it's disappointing that developer GSC Game World failed to address the problems with Shadow of Chernobyl that were left to the modding community to clean up.
If you've already visited The Zone and got lost in its nightmarish world and deliberate pacing, you'll find the landscape is still bleak and uninviting. You play as the silent loner Scar, a survivor of a strong emission originating from the nuclear plant at the center of the zone. His rescuers are the Clear Sky faction, a group of scientists investigating the reasons behind the emissions. And of course, their goal becomes yours as well. During your measured journey through The Zone, you'll visit other factions' headquarters as well, where you'll be asked to assault enemy bases, join their brotherhood, and perform tasks in exchange for information.
With so many bases scattered about, you'll soon discover that compared to its predecessor, The Zone is practically teeming with human life--though you shouldn't take this to mean that it's suddenly a carnival of cheery faces. This meatier population is borne out of necessity: Clear Sky's major new addition is that of factional warfare, in which the various packs of mercenaries (or in this case, stalkers) fight each other for turf control. As a result, you can meet the faction leader and join the team, assuming you've proven yourself worthy. This in turn means better merchant prices and other perks, as well as easier (or harder) passage to certain areas. Thus ensues a Battlefield style tug of war, in which factions fight over controls points in an attempt to take over the other's base.
Joining your teammates in these battles, like almost any combat situation in Clear Sky, is a nail-biting excursion into the unknown. Impressive enemy AI is one of the biggest reasons for this. Enemy stalkers make excellent use of cover, crouch and move away when they reload, flank you whenever possible, and generally react in plausible ways. They're tough cookies, so even at standard difficulty, you can't play as you would a standard first-person shooter. The only successful approach is to act and react as you would in real life: with caution and perseverance. Because of the slow flow of cash, you'll often feel spectacularly underpowered, but while these fights are often tense and difficult, clearing out a base with nothing but a pea-shooting pistol and an underpowered hunting rifle feels like a major accomplishment. Just be prepared to save. Often.
Over time, you'll find and purchase new weapons and armor, and can upgrade them with a visit to the right technicians at various bases. Unfortunately, enemy stalkers have a few tricks up their sleeves that border on the magical. Grenades are a nice addition to the series in theory, but foes have an uncanny knack for throwing them directly at your feet from huge distances. The implementation seems a bit off here; grenades explode very quickly once they land, yet S.T.A.L.K.E.R. has never been about quick movement (a stamina bar limits how much you can sprint and jump), so more often than not, multiple grenades usually means game over. The AI's uncanny ability to land shots, particularly at nighttime, also borders on the absurd.
These issues are most prevalent in two frustrating sequences that bottleneck progress in the first half of the game. In one, you emerge into a new area only to find yourself under attack from a nearby military installation. You're meant to run, but the eagle-eyed soldiers riddle you with bullets time and time again as you die and reload, wondering what the secret for escape is. In another, you must take potshots at enemies from behind a bus while dodging multiple grenades at once. Furthermore, this battle takes place a few feet from an exit point to another region; should you accidentally trigger it, your location will be reset to a few feet away, potentially on top of a grenade. Usually, Clear Sky is a tough challenge that makes you feel powerful when you succeed at your task. Sequences like these do the unforgivable: They yank you from the powerfully immersive world at the heart of the experience.
But what a world it is. Both new areas and old are desolate and freaky, and become more so as you move out of the swamps and carve a path to your destinations. Swirling anomalies threaten the simple act of trudging through the wilderness, and may pick you up and toss you about before you can escape. Packs of mutants, from wild dogs to leaping monstrosities, will descend on you as you scavenge for ammo, and it usually takes more than a single blast from a shotgun to defeat them. A journey through an underground installation becomes a fight for sanity as you get pummeled with psionic attacks that blur your vision. And in a heartbreaking moment, thugs attack you and take all your cash and equipment. Harsh, sure, but most of the time it doesn't feel unnecessary; it's just the nature of the world. You'll begin to think differently than you would in most games. How soon will night fall? Do I have enough bandages and radiation drugs (or the ever-helpful vodka)? What factions bar (or ease) the way to the artifact-harboring Garbage region?
Speaking of artifacts, those valuable, stat-enhancing objects are still floating within anomalies like before, but you aren't just going to see them and run in to grab them. Now you need to equip a detector, which will flash and beep when one is near, and point you in its direction. You won't see anomalies until you get very close, which means wandering directly into the radiation, grabbing the glowing bugger, and making a hasty retreat, usually while downing some vodka and using a health pack or two (here is one of those occasions where you will desperately wish the game let you bind radiation drugs and vodka to a hotkey). These are harrowing moments, but they make artifact collection feel meaningful, and just as you will tense as you wade into the danger, you'll feel equally rewarded when you walk away intact, brandishing your new glowing artifact.
It's too bad that Clear Sky tries so hard to make you not like it, thanks to any number of bugs and performance issues you may experience. The first main mission--assist a friendly stalker at a swamp outpost--is bugged: If you take a different route to your destination than the game intends, you won't trigger the script. In other cases, your faction leader may direct you to defend an outpost, but the attack will never come, or the promised reinforcements will never arrive, even if you wait for 10 or more real-time minutes (an eternity in video games). We experienced multiple crashes using a Steam-purchased, patched copy of the game, and a save-game corruption erased an hour's worth of progress. A retail disc would not run on one machine, because the copy protection program insisted there was no disc in the drive. Other annoyances also get in the way, from the inability to use the quickload key once you've died to hotkey settings that won't always save your changes. And over a year later, the engine remains unoptimized, delivering lower frame rates than you would expect on systems more than capable of running technologically superior games without a hitch.
However, Clear Sky doesn't look bad, and GSC Game World has managed to squeeze a lot out of an engine that was already lagging behind the competition when Shadow of Chernobyl was released. Lighting and shadows are outstanding, particularly if you have a system capable of using the newly enhanced light settings (good luck with that). Even without that system-wrenching addition, though, contrasts of light and dark are impressively ominous, due in part to the game's visually authentic day/night cycle. Dawn imparts a realistic orange glow, while midnight brings bleak darkness, punctured by the roaring fires in stalker camps. Bolts of lightning cut through the evening sky and dreary rain moistens the morning. Atmospheric effects like these are effective, taking your eyes off low-res textures, blocky geometry, and occasionally glitchy animations.
Clear Sky's ambient sound design is amazing. From the far-off howls of a dog to the roar and whoosh of anomalies, roaming about The Zone has never sounded so scary, and so lonely. No matter how many times you hear a mutant growl, the sudden outcry of one on your trail is always startling and chilling, and will have you glancing about, looking anxiously through the tall weeds. There are a few missteps in other areas, however. While much of the voice acting is fine, some characters sound like caricatures, like the squawking Freedom barman that offers to sell you marijuana (it's so grating, it may be enough to drive you to join the opposing Duty faction just to not hear him speak again). The base broadcasts you're pelted with when you visit faction headquarters are similarly out of place, and they detract from the atmosphere.
There's also a new multiplayer mode, but a week after release, we couldn't find anyone playing it--though Clear Sky's straightforward but slightly clunky online play isn't its main draw. You come for the atmosphere, and few games deliver dread and desolation better than this. Too bad it's as buggy as its predecessor, and throws in some new quirks of its own that break the spell. Nevertheless, while Clear Sky may get even better with some patches and fan modifications (much like Shadow of Chernobyl did), it's still a worthwhile journey through a stark world that, at times, feels all too real.