Move your trooper with WASD. He can walk left and right, duck, jump and double jump.
Pressing keys 1-4 will change your weapon:
1) Gun (single)
2) Gun (burst)
3) Gun (shotgun)
Aim and fire with the mouse. SPACE will allow you to enter your ship and use the more powerful cannon.
Use the energy from the insects to upgrade your weapons.
Press P for Pause and options.