With all due respect and admiration for Mr. Bulbapuck, I'm afraid I have to knytt-pic the tileset rule.
Making a new tileset can sometimes take weeks (it sure does me) unless it truly is just slapped together with no refinement. My thought is that an unrefined tileset would contrast with the tundra tileset more than any existing tileset known (though I haven't seen it yet).
If your worried we don't have the aesthetic sensibility to choose a tileset that will not contrast with the tundra tileset, why would we be able to make a new one that won't? Furthermore, why not choose a hand full of existing tilesets you think will go with the tundra set and let us choose from those? We should at least have some indoor tilesets, cave, or ice areas, right? Maybe some metal bunker stuff?
Just saying, limiting to one tileset or else make your own seems a little stricter than necessary.
Oh, and I've just looked through my public tileset and searched the forum and I can't find the tundra tileset. Anyone care to post it here?
And I guess I'll take slot #4.