Galactic Missile Defense

Mars picked a petty reason for war. A damaged picnic near a rover has pushed an alien fleet toward Earth, and three sealed military bases stand between the planet and a barrage of incoming ships. Galactic Missile Defense places the counterattack in those installations, with anti-missile batteries prepared for a long siege. Earth survives only if the line holds and the Martian assault breaks apart in orbit.

How to play?

Build up each base before battle by buying ammunition and battle aids. Load machine guns for rapid fire, then switch to thermal missiles or deploy lasers when the pressure rises. Plasma cannons add heavier shots. Time dilation slows the assault for a short stretch. An energy shield absorbs incoming damage. Launch a nuclear rocket for a large blast, or drop a black hole to wipe out clustered targets. Upgrade the defense network between attacks and reinforce the anti-missile system for the next wave.