Stonkers, by John Gibson, is one of the first RTS war games for the Spectrum, released in 1983, by Imagine.
You issue commands to your units and then watch them forge ahead, across variable terrain, towards the computer-controlled enemy. Units include infantry (men), artillery (cannons), armour (tanks) and supplies (trucks). There is also a supply ship which transits back and forth to your docks where you receive four more supply units when the ship arrives. There are various stats for each unit, supply, combat and mobility which show their strengths and weaknesses.
You use a point, cursor drag and click (fire) method to move your units. Fire also zooms in and out of the map. Terrain affects your unit's movement. Water kills your units. Fog of war is used so the enemy are only visible when close. Units must be re-supplied with trucks.
Units can die through combat or lack of supplies. Victory is achieved by occupying the enemy base or destroying all its units. Graphics are quite colourful for the map and units are identifiable. Sometimes there's a bit of colour clash, especially when units die as a skull is left behind and doesn't disappear for a while. Sound is limited to a zapping sound when you finish moving a unit and the ticker tape ticking. I really enjoyed this back in the day. There was nothing else like it and it was my introduction to RTS games.