use the arrow keys to move. Press the space to shoot. You have three lives. Different zombies give you different points. You can press x to use a nuke and destroy all zombies, but you lose 3 from your score. You can spend 10 of your score using a new gun by pressing c. Use 7 of your score to get one life by pressing v.
Tutorial on youtube: Scratch Tutorial | How to make a Top Down Shooter Game | Easy | Part 1
