Defender
In-flight mechanic
------------------
In some levels there are little tank-like units that remain
stationary. These are the units that shoot out the lightning
and repair structures. They cannot move on their own, but you
can pick them up to place them anywhere and they will slowly
repair any nearby units or structures. If you pick one up and
fly around with it, whenever you take on damage it will fix
your ship. Be careful though, because any enemies that may
shoot at you from below could hit it, and they cannot repair
themselves. However, sometimes it better to leave them near
your base so they will repair things as needed.
In-flight artillery
-------------------
If you need a little extra firepower for your ship, look for a
tank and pick it up. As long as you are holding the tank, it
will act like a rotating turret for your ship and fire upon any
enemy units that get within its range. The tank's cannons will
rotate 360 degrees so it can attack enemies all around you.
This is very useful if you do not want to deal with having to
make constant maneuvers to avoid being hit by an enemy that is
tailing you.