I've posted a couple of times here with two or three designs when similar questions are asked.
OK found it
A detailed indepth tactical squad based wargame that finally has all the features everyone wants straight off the bat. WEGO or some other form is fine though WEGO prefer. RPG elements. Squads with 1 man casualties like Squad Battles. Detailed comms. Tailor made urban combat mechanics. Multi level buildings, Sewers. Obstacles and IP's. SOP's. Off map arty. Air support. Para drops. Leader stats. Higher Command interaction.
A detailed man vs man scale tactical wargame. Indepth RPG features. Plus all the game above wants.
Detailed WW1 air combat tactical game. Use updated mechanics used in Achtung SPitfire and Flight Commander 2 so the actual pixel pilot skills effecting how well he performs in battle and if he can pull of the desired move you set. Darkwind on steam has a great car combat mechanic that if a z axis was added would be superb for this type of game. Squadron management. RPG features so you become attached to your pilots. Manage high command requests for next day objectives. A and B flight is a scout and C flight two seater recon. Deal with recon, arty spotting, bombing , balloon busting and trench strafing. The better your squadron performs the more skill points you can invest in air crew and the mess or trips to town to help nerves and fatigue etc.
Next a WW1 company trench wargame. Think Sims\Tower Defence\RimWorld\RPG\Prison Architect\Dwarf Fortress. You design your trench system improving over time and you manage your men and officers dealing with the weather, patrols, trench design and building, dug out design, orders from high command, giving leave, putting a man in for medal, defending German raids and patrols, intel gathering, the big push, aftermath of big pushes, different units opposite means sometimes live and let live and other times constant alert needed. If you get through the War maybe three or four have survived through it all and are still with you. Many dead and wounded, others promoted and transferred (you are informed of their deaths or if they win awards or say if join RFC have become an Ace etc to add immersion). You'll be able to see a list of all the men who have passed through your ranks and what happened to them this being updated constantly and be very interesting to read end of war. This game would be full of narrative and immersion. Create clever designed redoubts and see how well they stand upto attack etc. Position your MG's as more arrive over time. Forward liaison officers. Downed Pilots. Fix drainage issues. Fix hygiene issues. Periods in and out of the line. Out of the line arrange baths, football matches and lots of training if possible plus no doubt assimilate drafts. Lots of possibilities. Learn new training methods. New Arty methods men need training about. Mine and underground warfare.