If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Fly a Thunderbird during war and try to survive all the enemy attacks. Use your mouse to control your aircraft and it will shoot automatically. As you progress in the game, the enemies will become more powerful and they will begin shooting too. This is when your shield will be activated, but it also has a health of its own. Try to gather many power ups to help you survive longer and try to get the best score possible. Have a blast!