Coastal Defense is a free arcade game with beautiful graphics and simple controls. It has a nice soundtrack and an awesome background theme. You will have to protect your coast from waves of enemies by upgrading and expanding your arsenal of weapons. You will be able to defend yourself with several cannons, including some that you can find on the map and others that you can collect as you go. Some of them are more powerful than others, so you will have to choose wisely. You can collect money and diamonds as you progress through the game. These can be used to upgrade your cannons and increase their power. The more powerful your cannons are, the more money and diamonds you will be able to collect.