Final Scratch Game

I want my game to be a city with aliens or zombies. I want a sprite to make them disappear when they are clicked or use the mouse to click them away. The purpose of the game will be to get to a certain amount of aliens or zombies captured you will reach a certain level. I will draw the aliens or zombies or use a sprite. When the game begins the spite who is making the aliens disappear will say "Get the Zombies!" I will use a certain sprite to "capture" them. I will also make people spites and if you capture the people you will loose 5 points. I am going to use a background of a city. My scoring will subtract 5 points for a person and you will get 2 points for an alien or zombie. Once the player gets to level two the sprites will move much faster. After level two the aliens will go much faster. When the player finishes level two they will win and a text will appear and say "You won!"