To move the alien dude go left press the up arrow and to make the alien dude move to the right press the down arrow. To move the spaceship left press the left arrow, to move the spaceship right press the right arrow, and to make the spaceship go down press the space button. When the spaceship touches the alien dude he explodes and disappears. Then make the spaceship leave by pressing the space button.
Game
simple events, direction and turning, simple motion, visibility, simple sound playing, detect conditions,