From Hail 9 onwards the remaining levels are 100%.
Hail 10: Lemmy in the cold, cold, groundLemmings: 80
Time: 4 minutes
Release rate: 60
Skills: 1 bomber, 1 blocker, 5 builders, 5 bashers, 5 miners.
Bad: Gains no marks on decoration, as that chain behind two clumps of snow looks ugly. Several pieces in the wrong places...
Good: ...but that may be part of the title, as it's meant to be a cold ground. Involves a good deal of multitasking for several entrances, as this level requires 100%. A fairly interesting solution to execute.
Better than Blitz 10?: Hmm... both of them are multiple-entrance 100% levels. I'm going to say yes overall. There's more to this level compared to the other level, and the solution is neat and not too challenging. On the decoration front I would have certainly given the prize to Blitz 10, as that level is symmetrical unlike this one.
Oh, wait, that's not a backroute? I assumed that they gave you 50 builders because they intended you to build over the mountains...
Maybe so, but with only 6 minutes I don't think there's enough time to build over all the mountains. Still, I'll double check to see if this method works.