If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
You're under attack! Protect the mine as long as you can. If the Decepticons steal 100 units of Energon, The game is over. Use your mouse to position and fire the missile launcher. Watch your aim. Blow up the Energon and the game is over. Move the slider to change the velocity of the missiles.