Hy, the simple and straightforward pixel art graphics are really good, old school and smooth, like the 1990's. And the gameplay is promising.
Will you add walkable walls that infantry can't destroy ? This feature is missing in most games. Some of them that include it are awesome, like Stronghold or Civilizations ar War. I thought trying to make a prototype once, but never got time for.
It will require to implement pathfinding solutions and tweak ai targeting and taking decisions. Some work !
This would be a great addition ! Please, consider.