About me: War is war, either with sword, cannons or -in this case- mecha units, iron, blood, sweat and tears are always the same.
In the year 20XX mankind has reached a breakpoint as the Earth enters into fourth glaciation, with the temperatures plummeted, natural resources scarced and political tension growing the war was unavoidable, the Earth factions mobilised their armies and soon small scale conflicts were followed by large battles and higly cost offensives. It was a World War.
Earth has always needed of the technology and industrial power of the space colonies, but with the World War reaching a grduge stalemate the space colonies were pushed to take sides, but the colonies had enough of the prepotence of the Earth governments and replied demmanding more autonomy in exchange of their collaboration.
With the rebelliousness of their colonies, Earth factions started to extract natural resources to hold the war effort, pushing the small Mars colonies worsening living and work conditions creating a dangerous social unrest that added to the social and political unrest.
From sea to land, from ground to space and from Earth to Mars, mechas and space vessels, the cutting edge of technology and the bravery of their pilots is put on the line for a few metres of mud or just the emptiness of the space... that's the nature of war