I have a wish.. and its likley going to need mods.. that planet smashing would change the biome of a planet.. smashing a moon into a earth or tropical and then watching the planet slowly change into a lava biome around the area that got smashed (based on size of that smashed into it) be so awsom..
It's already confirmed that when an orbital body smashes into another orbital body it won't automatically destroy the entire planet. It'll depend on the size and mass of the two orbital bodies.
In retrospect, to make their work seem faster, it took Valve 12 years to finish Team Fortress 2, whoever made duke nukem over 6 years, and Totem Arts 5 years EVEN when starting with a prebuilt assets.
At least where Valve are concerned what they make is usually worth the wait... Duke Nukem on the other hand