One of the biggest surprises about the story of a video game coding whiz transported into a computer's mainframe is that after 28 years there are still not many games set in the awesome Tron universe. It started well enough with Bally Midway's 1982 coin-op, but slowed down significantly until the PC's Tron 2.0 in 2003 and Discs of Tron on XBLA in 2008. However, that is about to change as Canadian developer Propaganda Games has built Tron Evolution as a third-person action-adventure, which acts as a prequel, bridging the gap in story before this December's blockbuster movie release of Tron: Legacy.

The single player story mode is written for fans of the universe, with a script full of techno-gobbledygook that any Tron-buff will lap up but may leave some gamers baffled. It takes place on the Grid as its creator Kevin Flynn, the system's only human user, explains that some of the Basic Programs have turned on the evolving Isomorphic Algorithms (ISOs), because they are threatened that the ISOs appeared with their own functions, ideas and free will. Flynn's own program named Clu, which looks the spitting image of a young Jeff Bridges, is the evil orchestrator of the conflict and he has released a hooded virus called Abraxas to spread a blight and wipe out the ISOs. You must enlist the help of a program called Quorra who has contacts with Radia, the powerful spiritual head of the ISOs, to clear your name and bring about a new era of co-operation.

The parkour gameplay takes inspiration from Ubisoft titles like Prince of Persia: The Sands of Time and Assassin's Creed, involving plenty of free-running along walls and springing towards platforms. It mixes platforming with combat, and the battles are enjoyable as you learn that the key to each fight is never to stay still. Handily spread around each confrontation are Energy Transfer Conduits (ETCs) that restore your health meter, and energy pods to vault from to refill your energy bar. This bar enables you to unload powerful special attacks, so staying mobile helps you to balance your health and energy, and then attack with a combination of blocks, parries and chain strikes using your light disc.

As you progress through the seven chapters you acquire new light discs, assigned to the four selections on the D-Pad. These include a Core Heavy (increased range and damage), Core Bomb (explodes on impact), Core Stasis (slows target's movements) and Core Corruption (converts damage into health). Each enemy has a specific 'Defensive Protocol' and 'Attack Vulnerability', so you cycle through each disc to attack an opponent's specific weakness to add an element of strategy, although the visual design of the enemies can makes it difficult to distinguish them from one another.

Progress is linear but the action is broken up by vehicular sections and basic puzzles. The vehicle segments involve controlling a light tank to bombard your way though heavily defended environments, or racing to new areas on a light cycle. The puzzles are confined to searching for four switches which are each triggered by a light disc strike, or working out a twisting route of hand-grips and wall jumps to traverse an environment. Both of these are made fun as the game removes your guide, the Navi Bit, when you leave Tron City after Chapter 2 and it feels rewarding not to have your hand held to find a path. Traversing the stages involves avoiding corrupted sections of environment and comboing grapple points to progress, like in God of War III.

What is refreshing for a Disney title is that Tron Evolution is most happy when it 'derezzes' you, which is another way of saying that you will die, often. Throughout story mode there is an abundance of 'instant death' drops and the game takes an old-school pride in plunging you into them. Thankfully for the most part there are checkpoints positioned close to a derezz hot-spot, although you will still be frustrated from having to repeatedly play a number of sections in the game. There are three difficulty choices and it is not hard to complete the seven chapters, but as you mistime another wallrun leap through lasers you may find game progression to be a slog. You will also be infuriated with a boss encounter against two Light Tanks at the start of Chapter 6, as these opponents will kill you instantly by reversing over you, or if they catch you with their barrel. Whilst resorting to a kamikaze attack by leaping onto their turrets and crashing down with a bomb slam may not be the most strategic form of attack, it gets the job done.

Unfortunately the controls and camera can add to the frustration, there are moments when System Monitor plummets to his doom when you are convinced that the correct joypad input was not recognised. The game is built around fast reactions and smooth movement, in both its platforming and combat, but the camera can become lost and not keep up with the action. You will become more adept with the controls with practice, but will still experience cheap deaths as you become more skilled. The vehicles are easy to handle, although the light tank's movement is sluggish and slippery, plus its aiming is not always consistent.

Sadly, whilst the Move controller is supported as a single handlebar to control the light cycle, its responsiveness is too twitchy. Considering that the light cycle sections involve dodging scenery at high speed, the Move controls make this part of the game more difficult and less fun, so you are better off sticking with the DualShock 3. PlayStation Move support is primitive in this title and not at all a good showcase of the peripheral, feeling tacked-on at best.

The game has high production values, its audio is ambient and perfectly pitched for the subject matter, with a mix of original tracks and licensed songs from artists like Daft Punk. Graphically it attempts to add variety to its locations with a clever use of a dominant colour for each location, highlighting the difference between levels. There are even rocky green caves in the Outlands of Chapter 5's Bostrum Colony and a downpour of rain at the start of Chapter 7. However, despite a couple of random glitches, like a light cycle becoming stuck in a cliff, this game will impress most of all with its shiny and clean depiction of the gleaming Tron and Arjia cities, a striking mix of bold neon colours with a metallic shimmer giving this game its beauty. The last level, in which you navigate a bomb conveyance network of narrow platforms high above a gathering of Regulators, is the game's visual standout. It is worth completing the game just to revel in the wonderful art style used in the final chapter.

Tron Evolution may only have seven chapters, but each one is long and includes hidden extras, such as Tron Files and Abraxas Shards, which reward details of the backstory to gamers who explore the environments. The majority of the replay value comes from online multiplayer, in which ten players can compete or work together as a team in three modes: Disintegration (mass brawl), Power Monger (area capture) and Bit Runner (capture the flag). Each one is fun, especially on the more tightly designed environments and makes effective use of the free-running, fast moving focus of the gameplay. Best of all is a levelling up system in which you increase your System Monitor's 'Version' and save currency in the form of Megabytes. This allows you to upgrade your character's abilities, with all of the experience gathered being persistent and shared between your single player story and online multiplayer progress.

Conclusion

Tron Evolution's third-person parkour gameplay centres upon finesse and balance, but unfortunately its technical shortcomings do not create a stable experience. A combat system based upon constant movement is dynamic and there is strategy to selecting the best disc to exploit an opponent's weak point, but repeatedly plummeting down the same chasm is frustrating, especially if you feel as though the controls were to blame. The camera is not always able to keep up with the fast-moving acrobatics, a shame as the clean, neon-varnished visuals can be striking. Whilst the vehicle sections add variety, the Move controls for the light cycle are not well implemented.

The story provides a welcome extension of the Tron mythology, but the single player gameplay needs fine tuning. Alternatively, online multiplayer is fun as its level design is simpler which makes camera and control issues less prevalent. Story mode players should get used to the words 'System Monitor derezzed', over the course of seven chapters you will see them often.