The main object of the game is to build and send your troops to attack the enemy base. If a unit reaches the enemy base, it will damage it.
Once the enemy health reaches 0, you win the game.
When the game begins, first highlight/select any of the building sites and choose which building to construct. Certain buildings need to be built to make other buildings available. Each building has different properties, deploying troops, researching upgrades, etc.
You gain money every few seconds, the more income, the more money you gained.

Instructions:

Left click button on the building you want to use to see its availible options.
Repairs are located in the bottom left corner of the screen.