Trail Runner. A Retro 3D light-cycle game There’s no getting away from it. Trail Runner was inspired by ‘Knot in 3D’, a game written by Malcolm Evans back in 1983 for the ZX Spectrum. Happy Days Use the arrow keys to fly your ship in a wrap-around cube of space. You must avoid all the trails, including your own - the yellow one. Collisions affect your shield, when your shield strength reaches zero, it is game over. Your score increases in proportion to the increase in space density. Or just sit back and watch the demo.