Ever had the kind of day that just keeps getting worse, where you realise it was a terrible mistake to get out of bed? Well, whatever your worst day was, Gordon Freeman has it beaten. Within an hour of getting to work he finds himself fighting his way through a massive underground laboratory that has been half-destroyed and is infested with bizarre alien organisms intent on killing every human they can find.

Half-Life started out on the PC several years ago, so why would such an old game warrant conversion to the PS2? Because it's timelessly brilliant, that's why! Unlike games such as Quake III and Unreal Tournament, Half-Life has an excellent one-player adventure and it is this that will keep you going for some considerable time. You are Gordon Freeman, hapless scientist turned commando. The game begins in a sequence that would not be out of place in a film, as you ride an automated tram that takes you deep into an underground research facility. Once you arrive, you are greeted by the security guards and your colleagues as you make your way to the locker room and put on your protective radiation suit. As you head to the lab, you overhear snippets of conversations between other scientists that do not bode well and the scientists you are working for do not seem confident that their experiment will be successful. Unfortunately, their doubts prove right and a massive explosion rips through the complex, creating some kind of dimensional vortex that allows a host of alien creatures to materialise in the lab and go to work destroying and mutating the helpless scientists and inept guards. As the only person with a suit on, you are the best hope of fetching help and so you set off to try and reach the surface, but many surprises await.

If it sounds intriguing so far, believe me it is. The story that unfolds as you progress through the game is excellent, with a couple of great twists towards the end too. I don't want to say too much more and spoil the surprises, but let's just say aliens aren't the only enemy you have to worry about, someone much closer to home is determined to keep a lid on the accident at any costs.

Despite its age, the graphics and sound in Half-Life are outstanding, including highly realistic looking people and detailed environments. The graphics vary throughout the game and the scenery changes quite dramatically as you move through the complex. The sound effects for the weapons are booming, the aliens sound creepy and the voices are very good too. One of the most ingenious parts of the game is the usage of the scenery to move around. Because the complex has been damaged, you often have to seek alternate routes when doors and corridors are blocked. You will find yourself crawling through air ducts, jumping across pipes and precarious ledges and smashing through windows to name a few, creating an even greater sense of claustrophobia and realism. The routes are not always totally obvious, but once you get used to looking for ducts and ledges within reach, you shouldn't find yourself with nowhere to go. There are also various tasks to perform and puzzles to solve throughout the game, such as activating machinery or unlocking security doors that take a bit of thought and these added elements of puzzle and strategy serve to increase your interest in the game, without causing undue frustration or confusion.

"Get to the weapons!" I hear you cry. Very well. Half-Life has arguably the best arsenal of any FPS, beating the likes of Halo, Quake III and even Unreal Tournament. Pistol, shotgun, crossbow, magnum and assault rifle are all here, the latter of which fires grenades as a secondary function. The magnum is very satisfying to use as well and will drop most enemies with one shot. The rocket launcher can fire straight ahead or follow a projected laser, which you keep on the target as the rocket flies towards it, a very handy and original feature. All very standard so far though, right? Well, once you get hold of the grenades, trip wire mines and remote control explosives things become a little more fun. Later in the game you will also get your hands on a couple of alien weapons and two nuclear powered prototype guns that are super powerful. The arsenal is so varied and well rounded with each weapon being easy to use and realistic, maximising the fun of a good killing spree.

I would also like to mention that this game is huge and very tough towards the end. The difficulty curve is perfectly pitched so you will make progress but die plenty of times on the way. But the sheer scale and size of the game is truly awesome and I applaud its designers for providing such huge, varied, clever and enjoyable levels to play through, not to mention the way things suddenly change towards the end of the game (not to mention because I don't want to spoil it).

Half-Life on the PC is still one of the best multiplayer experiences around, but unfortunately what has been brought to the PS2 is merely tacked on so people won't complain too much. There are only ten small arenas to fight in with only two players, thus removing most of the interest of deathmatches.

There is also the welcome addition of 'Decay', a two-player co-operative mode. You and a friend can play the roles of two female scientists who are in the chamber below the one where Gordon is when the accident occurs. You then embark upon a series of missions that require you to work together to succeed and involve a great blend of shooting, skill and puzzle solving like the main game. This further serves to expand the Half-Life story and introduces new characters. The range and difficulty of the missions is generally pitched just right, but the lack of an in-game save feature means that you can end up playing through the first part of a mission over and over again because you keep dying at a certain part and this can get very tedious. Still, it's a great bonus extra and as with Halo, it's a lot more fun with a friend to keep you company.

Half-Life will forever be remembered within the ranks of Doom, Unreal Tournament and now Halo as being a groundbreaking game that brought innovative new ideas to the genre. It is a graphically excellent shooter with a superb arsenal of weapons, massive levels, challenging and intelligent gameplay, a great story and plenty of variety and surprises to keep you hooked until the end. The multiplayer mode on PS2 isn't worth bothering with, but the addition of Decay more than makes up for this and so Half-Life on PS2 is still worthy of a perfect score.

Reviewed by Geoff Holland for AceGamez (All Rights Reserved).