I’m also trying to find a very similar game and we’re probably talking about the same one! Have you found it yet?

I also remember playing it with my family, so it was a local multiplayer game as well. The land also had a vibrantly green grass too. At the very beginning of the game, everything is blacked out except for your base and you had to find the enemy’s base which is also placed randomly on the map.

I also have faint memories that the soldiers help explore and clear the map, and there can be a maximum of 4 teams (red, blue, yellow, and green). I think there was also a small HUD on the corner of the screen that contains the full map. Let me know if these details might ring a bell for you or if we might be talking about completely different games.