Scramble

Konami's Scramble is a horizontally scrolling shoot-em-up in which you must navigate your spaceship through five levels of varying terrain before facing and destroying the enemy base. The gameplay is quick, with missiles and enemy spacraft to dodge or destroy using your gun and bombs. Your ship's fuel depletes as you progress, and must be topped-up by destroying the fuel-tanks appearing sporadically along the ground. Although there are only six distinct levels, when the enemy base has been destroyed your ship is transported back to the start with a slight increase in the difficulty level. Scramble is a hugely influential game and has seen many ports and clones since its introduction in 1981.