Age of Empires: Mythologies for the Nintendo DS
One of the early testing sheets using a full background. A lot of my preproduction time was spent creating 3D units/buildings and seeing how those renderings would look against the background.
Dialing in the render settings included how much alpha blending around the edges would be acceptable. Units ended up having a lot more blending whereas the building needed to "pop" more against the background so I opted for less.