Cats vs. Ghosts

Tower Defense: Cats are towers, ghosts are enemies and humans are target. You must put the correct cat to destroy the ghosts.
History: Few months ago, something strange began to happen. Civilians reported seeing strange figures wandering the streets, causing chaos and destruction in their wake. Soon it was discovered that they were ghosts who had appeared in the town and seemed to have no friendly intentions.
As the days went by, the ghosts became more and more aggressive, and the humans began to feel helpless in their presence. But there was a group of beings who wouldn't give up so easily: the cats.
The cats, known for their cunning and bravery, began patrolling the streets at night, searching for any signs of the ghosts. When they found one, they pounced on it without fear, clawing, biting and shooting until it disappeared.
The humans couldn't believe what they were seeing. The cats, who normally kept their distance from them, were now protecting them from a supernatural threat.
No one knows for sure why the cats decided to defend humans against the ghosts, but some speculate that they did it out of love for their home and their slaves.
Since then, it's said that the cats are always vigilant, ready to protect their humans from any supernatural danger that may arise.