It's simple. Press the green flag to start. Move the mouse to control the cat. Chase the stars to get score. Avoid dinosaurs and octopuses, for both have negative effects when you are near them, such as the octopus ends the game, and the dinosaur resets your score to 0. Good luck and have fun!
Credits to: John Woodcock: Author of Coding Games In Scratch. This is my very first game, please love and favourite!