Environmental challenge anyone?

[Piotr Jasielski]

An environment on a foreign planet that contains organic life form and a structure built by the life that lives there

Sounds good for a first challenge.
If anyone has another idea please post it. We can make a poll and choose the favourite. If not, we can go with JonHop's idea.

Also, to make easier to keep the track, you can all subscribe to the thread.