Interplanetary Object Defense

You are a member of an infamous corporation that was somehow put in charge of defending the planet! Your goal is to survive as long as possible while collecting as many asteroids as possible to be mined.  Asteroids have gravity, and a portion will burn up in the atmostphere.  A small enough asteroid will cause no damage, but it will not be very profitable.

At your disposal is:

Gatling rail cannon -  Rapidly fires projectiles capable of breaking off pieces of an asteroid.

Massive Planetary Defense Flak Cannon - Launches many projectiles at once like a shotgun.

Tractor Field Projector - Attracts all objects in a large radius of the planet. Requires some energy to use.

Arc Planetary Defense Shield - Capable of bouncing asteroids of any size away, but must be aimed. Requires a smaller amount of energy.

Emergency Tractor Field Inversion Bomb - Produces a wave of force radiating outward from the planet capable of breaking large asteroids into many smaller pieces. Requires a massive amount of energy.

Controls:

'S' - Switch between Gatling Rail Cannon, and Massive Planetary Defense Flak Canon.

'Space Bar' - Engage Tractor Field Projector.

'Right click' - Activate Arc Planetary Defense Shield.

'Left click' - Fire currently selected projectile.

'B' - Fire Emergency Tractor Field Inversion Bomb.