Castle Defense is one of the free offline android games for everyone

Castle Defense is a subgenre of strategy games where the goal is to defend a player's territories or possessions by obstructing the enemy attackers or by stopping enemies from reaching the exits, usually achieved by placing defensive structures on or along their path of attack.

You can buy coins and make level up easy

The coin can be bought through diamond and diamond can be bought by in-app purchases and reward video.

Enjoy the game

Enjoy it.