The game is a kinda like a tower defense game. At the bottom left of the screen there is a start button which starts the round and spawns an enemy. The goal is to stop the enemy from reaching you in the room at the top of the map.You can place down troops to fight the enemy with right click and you can cycle through troops with 1, 2, 3. The space bar will center the camera on the enemy while a round is taking place. Other tips on how to play it are on the game page. hopefully that helps. Have fun.