The demo for Battle of the Sands contains a small tutorial campaign comprising three missions. It also contains three challenging stand-alone missions that you can play or allow the computer to play while you watch.
The basic controls are left-click-and-drag to select units within the selection rectangle; left click on a target point to tell your selected units to attack or move; right click to clear the current selection; left control + a number key to assign a group number to the selected units; number key to recall the corresponding selection; and left click on a building icon to start producing that building.
Once a building is ready, left click on the icon again then left click on a point on the map to place the new building.
To start producing tanks, left click on a factory then left click 'Start Production'. You can scroll the map with right-click-and-drag, or by mousing on the screen's edge (full screen mode only). Switch between full screen and windowed mode with Left Alt + Enter. Save a screenshot with Left Alt + X.