In the online strategy game Merge Defense, your only goal is to protect your base.
It has a diamond inside that a lot of monsters wanted to steal. They need to stop. To do this, you need to build defenses that will shoot at your enemies and keep the diamond safe. The famous mechanic of merging is also in the game. You can combine buildings of the same type to make them stronger. You can also go to the store and buy new improvements there.
Have fun and good luck!