Cubefield

Cubefield is one of the most famous browser games ever made, and it only needs two keys. You control a small triangle sliding forward across an endless flat plane, and the left and right arrow keys (or A and D) shift you sideways between the columns of cubes rushing towards you. There is no brake, no jump and no shooting: your only job is to thread the gaps without clipping a single block.

The difficulty comes from acceleration. Every few hundred metres the field speeds up, the cubes pack closer together and the background colours shift, which is the game's way of telling you that you have reached a new stage. Your score climbs continuously while you are alive, so a great run is measured in how long you can keep your nerve once the walls of blocks start flashing past faster than you can react. The trick most high scorers use is to look far ahead rather than at the cubes right in front of the ship, and to make small taps instead of holding a direction down. If you enjoy this kind of pure reflex speed test, try Tunnel Rush next.