They say graphics aren't important - but every game I've ever played has had them. Game visuals are the most obvious indicator of their technology. From naive origins, to an explosion of arcades and home consoles, and the emergence and refinement of three-dimensional games: graphics have come a long way over the course of video game history. So, what are the most important graphical milestones? How has available technology shaped the type of games we play? And shouldn't it be about the gameplay instead? In their earliest days, video games amounted to little more than electronic novelties. These pixel pioneers broke new ground with every step - in an era when simply moving a flicker of light across a television screen was incredible. Games like Pong were a space age wonder, tapping in to a surge in sci-fi interest and becoming the earliest major success of the video game industry. For the first time ever, video games were cool. It wouldn't last forever, of course - and once the novelty wore off, the need for more advanced hardware - and more impressive visuals - became clear. Full-colour graphics were an early threshold for arcade games: and while colour television had existed since before the second world war, most early video games were limited to a monochrome display. Some games used coloured overlays to spruce up their playfields - a translucent plastic sheet applied on top of a black and white display. Obviously quite a limited solution, but it was at least a cheap one: and while monochrome games continued to rake in coins, technology would have a chance to catch up. The very first arcade game to use a coloured display is difficult to pin down - some existed only as prototypes, such as a colour variant of Gotcha! Some early multiplayer racing games used colour to differentiate each player's car: Indy 4 in 1976 is one early example, and Car Polo in 1977 was the very first colour arcade game to use a microprocessor. These early examples are normally glossed over in favour of the first truly successful RGB colour game: Galaxian. Essentially a fancier version of Space Invaders, each of the brightly-coloured alien ships could flit freely across the screen: and perhaps more impressive were the multiple colours used in each sprite - for its time, the game was an audiovisual treat. By 1980, colour graphics were the norm: Pac-Man just wouldn't be the same without its colourful ghosts and the familiar yellow protagonist. Pixels haven't always been the norm. In the early days of the arcade, there were two principal paradigms for rendering an image on the screen: raster and vector. Raster comes from the latin word 'rastrum' meaning rake, - and today is the more familiar method of drawing on-screen. The electron beam rapidly sweeps every line of the display in sequence, forming a grid: and line-by-line, a picture is assembled. Vector graphics directly manipulate the electron beam to form their images, in a similar manner to an oscilloscope: indeed, very early games like Tennis For Two used an oscilloscope display. The most famous vector arcade title is Asteroids: and while its graphics might be sparse, the perfectly smooth polygons do boast a certain charm. Compare the appearance of two similar games using each of these methods: the smooth vector lines of Space War! versus the blockier pixels of Star Cruiser. Vector graphics are cleaner, but less versatile: while raster images can't reproduce smooth lines, their ability to render more complex scenes and filled shapes helped to secure the pixel's dominance. Early arcade games normally had fixed playfields: a game's arena was sized to fit the screen. Scrolling the display to slowly reveal a level required more grunt: it demands the ability to shift around large chunks of memory. Early driving titles like Speed Race were the first to introduce scrolling, although the hardware limitations did force some concessions: mirrored tracksides and a rather spartan roadway. Defender in 1980 was an evolution of the space shooter, and set the scene for future side-scrolling shoot-em-ups: despite its simple graphics, it offered freedom of movement across a planet's surface - along with a host of aliens to shoot. Similarly, the top-down view seen in Xevious is often cited as the origin of the vertically scrolling shoot-em-up: with the player's ship at the bottom of the screen shooting upwards as the scenery slowly unravels below. SEGA's Zaxxon was the first isometric game, complete with isometric scrolling: simulating 3 dimensions with a 2:1 dimetric projection. This technique was employed by many later games - particularly strategy games of the early 90s - with a psuedo-3D appearance that still fits the pixel grid. Similarly, the use of sprite scaling - resizing images on the fly - is sometimes seen in games attempting to lend their otherwise flat graphics a sense of depth. Early Nintendo shooter Radar Scope shrank sprites in the distance to give the impression that you were gazing across a plane of space: the goal to repel any invaders. More impressive was the scenery in 1981's Turbo: although painted in garish colours, and with quite some distortion - the effect is nonetheless outstanding when compared to other games from a similar time. The advent of 16-bit arcade hardware brought about more colours, and the ability to shift more pixels than ever before: and SEGA's 'Super Scaler' tech in the mid-1980s blew everything else out of the water. Truly, a new era was beginning. Hang-On combined smooth sprite scaling with blistering frame rates - and alongside its impressive lean-to-steer motorbike cabinet, it certainly made an impact at the arcades. Running on the same hardware was Space Harrier: an into-the-screen rail shooter that would set a benchmark in sound and graphics: as well as establishing the basis for the Top-Gun inspired After Burner. Perhaps the most incredible graphics of the early 1980s were those seen in Dragon's Lair: leveraging the huge storage potential of laserdisc technology, it was a bona-fide interactive movie. Too bad it wasn't much fun to play. The middle of the 1980s saw the end of the arcade's golden era, and the rise of the home consoles instead. Arcades would still rule the roost as far as graphical power was concerned, but the ground they broke earlier meant that cost-reduced home consoles could deliver both colourful graphics and smooth scrolling. Join me in part two for the next stage of video game graphic development: a time when two-dimensional games reigned supreme; and sprites were in their prime. Until then, farewell.