I want to think you're not serious here, but somehow I think you are.
The eastern front was full of trench warfare, just spread over longer lines. Other than the landings and the eventual retreat, the entire Gallipoli campaign was just one of the biggest trench standoffs of the war, outside of Verdun.
If you want something different, like I said, air or sea battles, or perhaps something like German East Africa where actual moving fights took place occasionally. Basically all of the EU and Ottoman fighting was trench warfare, starvation, disease, attrition, etc. You'd have to do specific conflicts in the colonial regions or maybe highlight the spy missions to make something worth playing.