Sky Shark (1987)

Sky Shark (released in Japan as "Hi Sho Zame", and in Europe as "Flying Shark")is a military-themed vertically scrolling shoot 'em up game in which players take control of the titular biplane through five increasingly difficult levels in order to defeat an assortment of military enemy forces like tanks, battleships, airplanes and artillery as the main objective. The title initially appears to be very standard, as players control their plane over a constantly scrolling background and the scenery never stops moving until a runway is reached. Players have only two weapons at their disposal: the standard shot that travels a max distance of the screen's height and three bombs. The bombs are powerful weapons capable of obliterating any enemy caught within its blast radius. Various items are scattered through every stage that appear by destroying certain enemies: Shooting down colored waves of enemy planes spawn items like "S" power-up icons, point bonuses and extra lives. Certain enemies on the ground spawn "B" icons that increases the player's bomb stock when destroyed. Every time the player lands at a runway beyond the first takeoff, the amount of bombs multiply 3000 points to the player's total score. Players are given three lives initially and bonus lives are awarded at 50000 points and thereafter. The game employs a checkpoint system in which a downed single player will start off at the beginning of the checkpoint they managed to reach before dying. Getting hit by enemy fire will result in losing a live, as well as a penalty of decreasing the plane's firepower to his original state and once all lives are lost, the game is over unless players insert more credits into the arcade machine to continue playing. Completing the last stage restarts the game with the second loop increasing in difficulty.