Ionic is a space based RTS / Defense game with elements of classic horizontal shootem ups.
Command your mothership turrets to survive a massive space battle by building your turret battery on the hull.
Although Ionic is an obviously tower defense game at heart, the developers tried to avoid some of the more common cliches by trying to move it into the direction of a shootem up.
The game has a small initial learning curve.
Use the mouse cursor to place, order and repair your turrets.