Ricochet bullets to kill as many enemies as possible with each shot. The more soldiers you kill with a single shot, more ricochets your bullets will add.
save ammo to get more medals in the level. More kills with single shot, more points you get.

Your own shots can hurt you but if you do nothing you will be crouched and safe.Enemy shots and your own shots will not be able to reach you. But when you are aiming you will be vulnerable be careful that the soldiers do not aim at you or be hit by your ricochet.

Your ammo is limited, think carefully where to aim. If you get hit by a bullet or run out of ammo you will fail the level. Unlock levels by getting at least one medal in the previous level.