

Introduction
I first heard about Garry's Mod about a year ago while watching G4 television. The idea was simple enough: a sandbox for Half-Life 2. The usefulness was also simple enough: nil. In Garry's early stages, there was absolutely nothing to do but spawn items and throw them around in a lone "construct" map. Now however, Garry is up to version 9 and his mod allows the player to do basically anything they desire.
Garry Newman, the creator of Garry's Mod (hence the name), has done an excellent job of achieving his goal to create a sandbox modification for the Source engine. Throughout his development stages, he has amassed a team of over 10 programmers, mappers, and modelers to help with his popular modification.

This particular modification is a bit unorthodox in that it has no real "content" - there's no story or scripted events or anything. The mod itself is all about playing with the Source engine, its physics, and spawning items and characters into the world. It's all about FUN.
Installation and Setup 4.5/5
Garry's Mod is easy install: visit Garry's web site or your favorite file distributor such as Fileshack and download the 26MB file. Yes, it's nice and small so it's a very quick download. Double-click on the installer and the mod will pretty much install itself from there. Next, you simply have to restart Steam and the Garry's Mod icon should appear as one of your installed games in Steam.
System Requirements: Garry's Mod includes no "new" content and as such contains the same graphics and audio features as the rest of the Source engine games. If you can run Half-Life 2 or any other Source game, you should be perfectly fine under Garry's Mod.

Graphics 4.5/5
On par with the rest of the Source engine games, Garry's Mod has excellent visuals - especially if your machine can crank out the frames at a high resolution with AA/AF. The game's texture quality still impresses me, even though Half-Life 2 has been out for some time now.

So long as you meet Half-Life 2's minimum system requirements, you won't be disappointed with the aesthetic experience provided by Garry's Mod.
Maps/Levels 4.5/5
Garry's Mod adds a few new maps to the Source engine's collection. The most useful map in this mod is the standard "Construct" (think The Matrix). There are a handful of other maps which can be used specifically for Garry's Mod but the coolest part here is that the mod can load nearly any Source engine map - that means that you can load cs_italy from Counter-Strike: Source or even the river chase scene maps from Half-Life 2.

Sound 4.5/5
The sound in Source engine games is, as you probably know, quite good. The old, familiar hum of the gravity gun makes its return and you are treated to a satisfying "thwap" when you use Garry's physics gun to throw an inanimate pigeon body against a brick wall (more about this later).
Gameplay & Controls 5/5
The great part about PC games is that you can customize your controls completely. In Garry's Mod, the only really new control is the 'q' button by default: holding this button down opens a menu where you can pick what you want to do. Here, you can spawn any kind of item including non-playable characters, small items such as watermelons, inanimate enemies such as antlions, pots, pans, computer monitors, radiators, junked cars, and even that huge brick chimney that falls on you in the river chase scene from Half-Life 2.
Of course, you are well equipped with the standard weapons so it's always fun to build a stack of watermelons (you can spawn one watermelon, then select the "duplicator" mode under the 'q' menu and simply copy the watermelon as many times as you want) and drop a rocket-propelled grenade into the center of the pile. When I did this, my framerate literally died and it took my computer a few seconds to realize what was going on. Watermelon chunks flew everywhere. It was great!

I briefly mentioned the physics gun earlier in this review. The physics gun allows you to grab onto anything and throw it around, spin it, flip it, freeze it in midair, or manipulate it in any way possible. That said, you can spawn a pigeon and throw it across the map if you want to. It sounds sick and disturbing, but you know you want to try it!

Another great thing you can do in Garry's Mod is spawn non-playable characters and arrange them into any position you want - humorous, embarrassing, or otherwise. You can even edit their facial expressions! Here I have set a lovely red couch on the middle of an isolated island in the Construct map (the standard Garry's Mod map). As you can see, Barney and Lamar can get along after all!

My final favorite activity in Garry's Mod is getting revenge against that darn G-Man. You know how you always see him off in the distance but never seem to catch him? Well, I decided to (using the rope tool) tie him to the bumper of my buggy and drag him around for a while (Achilles vs. Hector style).
As you can see, Garry's Mod offers plenty of very silly opportunities. You can create your own Kodak moments, mess around with the Source engine's physics, throw some stuff around, blow apart some water melons, or shoot some clay pots in the air and watch them shatter when they hit the ground (also highly recommended). I've also heard about some creative players using Garry's Mod to craft custom scenarios to play through in Half-Life 2 or Half-Life 2: Deathmatch. What I have told you here barely scratches the surface of the possibilities offered by Garry's Mod: it also allows you to customize and make working NPC's and creations such as a dumpster which floats around the level because it is tied to several balloons (and yes, you can ride in these contraptions you build). Try spawning a bathtub and tying saw blades to it as wheels, then attaching some booster packs - hop in the tub and ignite the boosters for a fun ride! There is so much more to tell about Garry's Mod, but in the end the possibilities are limited only to what you, as the player, can think up.