Once upon a time (to use an old cliche), there was a Quake 2 modification called Gloom. Pitting Aliens versus Humans in a sci-fi environment, it spawned two spin-offs: Natural Selection and Tremulous. While Natural Selection has since moved on from its source material to carve out its own niche, Tremulous continues to carry on the spirit of Gloom in truest fashion. It's a worthy freeware remake that adds its own flair. That's always a good thing.

Tremulous is not a very pretty game. There's just no escaping it. The textures are not particular high-resolution, and neither are the models. The animation can be jerky and stiff. However, that being said, the art style is very consistent. While nothing is just absolutely stunning, it never pulls you out of the atmosphere of the game, which is really the entire point of art in a game. Nothing pulls you out of the aci-horror sci-fi experience that Tremulous breeds. The sound is similarly good. While it is not quite to the paranoia-inducing levels of Natural Selection, it definitely gets you pumped for fights against the alien creatures. The music is not of major importance, as you won't really be paying attention to it throughout the game.

There are two teams: Aliens and Humans. Each team is different on a fundamental level, with the Aliens focusing more of classes filling specific roles and Humans being weaker overall but more versatile and customizable. The Alien classes are acquired by killing other players, and most forms have an advanced form that unlocks an extra attack. The classes are as follows, and if they don't have an advanced form, they will state so:

• The Granger is the basic builder unit of the aliens. He is what creates all the different structures that the aliens use. His most important function is locking down the humans, as effective placement of defensive structures stops a human offensive push cold. His advanced attack is a simple ranged attack.
• The Dretch is the weakest combat class and doesn't have an upgraded form. It can run along walls and attack human players, but is weak in just direct play. The Dretch relies on sneaking and headshots (bites?) to eliminate human players.
• The Basilisk is the basic combat class that most alien players will learn first. They are much like the Dretch, only more durable and with an ability that stops the human player from moving. Much like the Dretch, the Basilisk can crawl along walls to surprise human players. His advanced attack creates a poisonous cloud of gas.
• The Marauder is a middle-of-the-road unit of the aliens, mixing the speed of the lower-tier classes with the power of the higher-tier classes. The Marauder only has one attack, but is more durable and can bounce off walls like a pinball. His advanced attack is chain lightning that jumps from target to target.
• The Dragoon is the tank of the Aliens with a powerful regular attack as well as leaping attack. His advanced attack shoots barbs at enemy players to deal damage from a range.
• The Tyrant is the ultimate class for the Aliens. Incredible toughness, a slew of good abilities (such as increased team regeneration), and powerful default damage make it the choice for assault on entrenched enemies.

The humans are quite strong as well, but in a different way. Unlike the Aliens, players don't choose classes, but rather a load-out. This load-out includes utility items, armor, and weapons. For example, a typical assault load-out might be a Lucifer Cannon, Medikit, and Battlesuit. Your load-out is determined by your cash, which is increased through skillful playing. The modularity of the Human team is their strength; unlike Aliens, Humans are a lot less specialized and a lot more versatile. They are also long-range oriented, as compared to the almost exclusively close-range Aliens.

There is only one real gametype to vanilla Tremulous, and that is to simply annihilate the enemy team. Humans must destroy the Overmind structure and kill all the Aliens, and Aliens must destroy all of the Telepad structures and kill all of the Humans. Multiplayer Tremulous is mostly the default (or vanilla) game, with a good (but not extraordinary) selection of active servers available for players to play on. Tremulous is, however, much more mod friendly than most free games, as it is completely open-source. Using the open-source Quake 3 engine as a base, Tremulous has expanded upon it and can be modded to do all sorts of things. It's not the best platform for modding, but the fact that it's a free game that encourages modding is unusual. Not many games do that; the last game that springs to mind that encourages plentiful modding is Battle for Wesnoth.

Tremulous is, quite simply, a fantastic multiplayer first-person shooter. Following last weeks article on Smokin' Guns, which is an excellent multiplayer experience in of itself (and also based on an old Quake 3 mod!), some variety was needed. We have shown off a good freeware multiplayer western shooter, so it's time for a good freeware multiplayer sci-fi shooter. Tremulous is that game, and it is strangely addicting. You can download Tremulous on PC or Linux through the official site, and both the normal installs and source code are available for consumption. The manual is also available on the official site and explains the classes and weapons in much more detail.

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