Game's genre is "active" line defense.
You will have to protect your planets from hordes of invaders.
For effective protection you can choose four units of nine unique.
Swordsman, Archer, RifleMan, Sniper, Heavy soldier, Ninja, Medic, Energetic, Tesla trooper, Robot.
You can learn up to 4 skills for each unit.
You will find:
15 exciting levels.
9 unique units.
12 types of enemies.