If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
The robots are coming... To eat CAKE! You must stop them from getting their mechanical claws on the cake. It's your job to shoot all the robots before they can get to the cake. Thankfully, if you kill enough mechanical beasts, power ups will help you. Make sure you use them wisely as they can make the difference between saving the cake and losing it forever.