In this game you need to beat you opponent by destorying the red castle with your mighty troops. In the upper left corner you can see your kingdoms gold. At the right side of your screen you can buy your legendary troops. The cost is displayed underneath the unit. If you buy a unit it will be put in the spawning queue. This means it might not appear instantly but will eventually spawn if there is enough space for the new recruit.
There are serval cheats in the game that will help you test the application.
The numbers are simply the cheats just press the number on you keyboard and the cheat will be activated