Angry Ball Swarm is an action game, where you don't have any offense, you only have defense as your ability, so take control of others to use their weapon against each other.

3rd party asset: Kenny's Particle 2D

Controls:

W to move forward, A/D to move sideways.

Left click to activate shield

Right click to take control of foe.

Space to attack.

Let me know if you managed to defeat the boss, or at least seen one.