Concept art is the available only in Battalion Wars 2 or BWii. (突撃!!ファミコンウォーズVS, Totsugeki!! Famicom Wars VS).

An example is below with the Iron Legion's Battlestation.

To view Concept Art:Edit

You have to unlock it by obtaining S rank campaigns in the Story Mode.

Once obtained, you'll be able to view it in the "Extras" option within the game.

Battlestation image

The Iron Legion's Battlestation.