Other Portal 2 Easter Egg

[Necrius]

I think it should be possible to shoot Portal Gun into the moon and die upon entering a portal with a message "<playername> was craving for SPAAAACE too much".
Or even better - Moon biome made of moondust and moonrock with occassional cheese veins.

 

[SnailsAttack]

Maybe the first one, but not sure how it should work. Also, I think that the player should just instantly die and say '<playername> forgot there was no air in space.'

 

[Weetile]

And include Wheatley and the Space Core as enemies!