Some suggestions...

[Xriqxa]

Collision fix:

I've noticed that when collisions occur a stream of particles and asteroids fly out, but do not continue spawning as the object proceeds to sink into the body, which leaves a rather silly looking ring of particles zooming away from the blast site. Perhaps they can be continuously spawned as the object gets absorbed?

Atmosphere tear away:

If a large enough body collides into an atmospheric planet there could be an animation of the air peeling of the planet. After a collision the atmosphere shouldn't re-condense IMO.

[Mrclimix]

They did say in one video i think or a comment in a video that they would do the atmosphere tearing away or blasting the atmosphere once a planet,moon,asteroid is seconds from impact.