If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
On the flaming fronts of World War 2, the headquarter dispatched a sharpshooter sniper to fight in the pioneer in order to cut a road to capture the main cities. Now lock your target and shoot them on the head!
Space bar to open sniper mirror. Mouse key to aim, left click to shot. A to hide, S to recover.
Note: When the red exclamatory mark appears, be quick to hide.