I simply would like to hear what uber's opinion in this. This game type can be in FFA or TEAM games. It is called Armageddon. Going past a 40 minute timer the world begins devastation and falls apart slowly damaging units and Commanders. Armageddon can be multiple things like meteor showers hitting the planet, or lava slowly filling up the planet damaging units. Of course Armageddon will stop once their is one remaining Commander.
One of the possible modes we've talked about internally, as well as on the LiveStream, is two planets on a collision course. You have until their respective orbits indicate a collision to either win, or get outta dodge. As described, I think it would be great for a mod or for non-competitive gameplay, but it would be hard to balance "disasters" unless you could make sure they hurt players equitably, which is hard to do in a procedural generated solar system and with bases that can span multiple planets.
Could have it so intersecting planes have a little dodge animation where they go belly to belly past each other.
If you can ensure start locations all start at a particular height, could you have a "water rising" scenario? It wouldn't mean game over (can transfer to naval), but if the planet starts out as mostly land, it would cause an interesting dynamic change.
unstable sun producing massive radiation output on sunny sides of planets, damaging units over time? as planets rotate it should be fairly evenly spread across planets and comparatively easy to implement as you just need to map the damage against the light from the sun, which can link in with the existing lighting model.