This is a tower defense type of casual game, suitable for you to pass the time when bored. In the game, enemies stream out of the portal, and you can destroy them by building defense towers. For each enemy killed, you get a certain amount of gold. Since enemies get stronger as the game progresses, you'll need to build new towers with the gold you earn. When the total number of enemies exceeds a certain number, the game is over. Of course, you can also buy items in the store, and with the items you buy in the store, you can kill a certain number of enemies in an instant.