Back in 2001, Rez was released on both the PS2 and Dreamcast, offering a truly unique experience with its mix of rail-based shooting and use of electronic music. The inventive visual style also helped contribute to the game's 'trippy' nature. Here we are in 2008 and that cult classic has been ported to the Xbox Live Arcade, with an HD upgrade. Besides that, nothing too significant has been added, but Rez still offers an amazing experience seven years later.

Rez is not a story-driven game by any means. If you look through the menus you'll find a small synopsis of the plot. You play the role of a hacker whose avatar is hurled into a futuristic computer network called the K-project. The network is controlled by an artificial intelligence: Eden. The flood of information running through the network has caused Eden to enter a shutdown stage, which would cause more than a few problems. So you must navigate the network, destroying viruses along the way, in an attempt to prevent Eden from shutting down. The lack of a compelling story may seem like a problem, but this is a non-issue thanks to Rez's addictive gameplay.

Anyone unfamiliar to videogames will have no problem picking up and playing Rez, so gamers will find it to be like riding a bike or tying your shoes (hopefully those two things are easy for you!) This is due in large part to the fact that Rez can be played using only the A button; that's right, ONE BUTTON! The game moves your character along a preset path, so you don't have to worry about shifting all over the place to avoid attacks; you just focus on wiping out your foes. Holding down the A button and moving the left analog stick over an enemy will lock onto them. Release the button to attack, and you're done. You can lock on to a maximum of eight targets at once, which comes in handy when you've got multiple enemies coming at you. This doesn't mean that Rez is devoid of any challenge though; in fact, the latter stages can be quite difficult with so many enemies, and the end of each level provides you with a formidable boss to square off with. These boss battles are a highlight, requiring a specific strategy and offering a new challenge each time.

Actually, the A button and left analog stick aren't the only controls in the game. Using the B button activates overdrive - on the bottom right corner of the screen are the four overdrive bars that can be filled up by collecting small red polygons, which are obtained by shooting them. Filling the bars and activating overdrive results in a wave of shots headings towards your enemies for a short period of time and also collects any other power up items on the screen. Those other items are blue polygons that basically give you health, represented by other bars on the bottom left corner of the screen, similar to overdrive. An interesting twist is that filling those bars with power ups evolves your character, changing its appearance. Damage can result in you reverting back to your original forms, until you're a small sphere and one more hit equals game over. Take all of that in and you've got a nice balance of simplicity, depth and challenge.

Often a game's visuals are certainly pleasing, but not essential. Rez's graphics, on the other hand, are one of the game's driving forces. The explosion of colors and shapes really immerses you in the world - or the network, I should say - that Rez provides. The same enemies are recycled sometimes and their design isn't necessarily clever, but these are only minor gripes. Obviously the game isn't a technical marvel, but it doesn't need to be; the creative art style is just as impressive as a game that perfects animations and environments. Just like with the visuals, Rez's audio is one of the most important factors in the game. In fact, it intertwines with the gameplay. Rather than an explosion or crash when you hit your enemies, you hear little electronic sounds that integrate seamlessly with the techno soundtrack. Once you really start getting on a roll, you feel like you're adding to each song, not that you would need. The soundtrack is excellent and fits in perfectly with the gameplay. The best part about the music is how it builds up as you're playing; each stage features ten sub-levels and completing each sub-level adds a new layer of music, until the tune has transformed from something fairly sparse into a full blown techno song, blasting out of your speakers. If you play Rez for hours on end then the music might wear thin, but that depends on the person; when you pair the visuals and audio, you start to feel like you're spiraling into a trance-like state, especially if you're playing in HD. That's right, there's no need for harmful drugs - just play Rez!

Rez takes the approach of quality over quantity, and it works for the most part, but that doesn't mean that some won't be disappointed with its length. The game can easily be finished in one sitting, but there are some extra game modes to keep you playing after you've completed it. After finishing each stage you can try the score attack mode, aiming for the best score you can get in each area; those looking to climb the Xbox Live leaderboards are sure to spend a lot of time here. Also unlocked after beating the game are lost levels and the game modes Direct Assault and Boss-Rush. The lost levels are like the deleted scenes of a movie; they didn't make the game but they're still pretty entertaining. Direct assault starts you off at the beginning of the game and it's your goal to reach the end without dying. Boss-rush, in similar fashion, challenges you to defeat all of the bosses in succession. Both of those modes are tough, but they're worth a shot to see how you fare.

Whether you played Rez back in 2001 or missed out on it, you should snap up Rez HD. The same creative gameplay, visuals and music are still there, along with some welcome additions that are sure to satisfy those who have played the game before. Sure, Rez HD isn't perfect; although the gameplay is fun, it may be too simple for some, and it doesn't offer a whole lot after completion. But for 800 Microsoft points, Xbox 360 owners are getting a fantastic game that is up there with the very best that the Xbox Live Arcade has to offer.

Reviewed by Anthony LaBella for AceGamez (All Rights Reserved).