Tap the screen to navigate Dr Green Alien through the space adventure. Collect the toxic waste barrels to accumulate points. Avoid obstacles and enemies that may impede your progress. Get to the finish line with the required number of barrels to conclude the level. Utilize the arrow keys or swipe gestures to control Dr Green Alien in different directions. Be cautious of the poisonous barrels and strategize your path carefully. Move forward through various levels, each with distinct challenges and layouts. Improve your precision to increase your score and reveal new levels.