Defend the space carrier with a turret by gunning down as many enemy spaceships as possible. Get additional help by sending out carrier fighters of your own.
Send out units to take over other territories and win the battle by taking full control of them. Then it'll set free of all territories from the dark force.
Drive as fast as possible to the patients location and transport him back to the hospital carefully while not injuring him more. Get insurance payouts for each successful transport of a patient in order to upgrade your ambulance van.