ANAND: I've seen your 3 last maps.
Ice Age: interesting map with symmetrical terrain, will be so funny with slippery nodes! I'm already imaginating the number of hilarous fails we will have on this map when a player runs and… can't stop himself!
The maps is not very deep, that can be a bit annoying, we will quickly reach the bottom. Anyway there must be an unbreakable stone barrier at the bottom (players sould never be able to go below). That's ctf_map that, for now, doesn't set it. I'll see if I can edit the schematic to place the barrier.
Underwater: pretty good map too, the darkness of the seas will make fights more difficult. It's more than 20 nodes deep, so we will have the possibility to widely use the vertical dimension for moving, which will change the strategy when chasing a player, or escaping! However I wonder if it would not be a bit boring since it's not very varied.
I found the 2 spawn rooms, and since they are under the sea bed, I'm worrying about players that will dig the ceiling and flood the base. It's part of the game if an enemy does this but most of the time it will be done by base's (noob) players. Perhaps at least the ceiling should be unbreakable.
Sky: I think the platforms are currently too much spaced, there should be more ones. Will be good with platforms at different heights; it will still be a hard map. A big proportion of deaths will be due to falling in the lava. Just consider the number of players on the Caverns map that die in the lava, which is yet not difficult to avoid. And the items they have when falling will be lost forever. I don't know if you have considered it, after all this can be part of the game. Items becoming rarer and rarer, the last player that has a steel sword will basically win the game.
Anyway interesting concept, will reproduce SkyWars but with a more motivating goal.
Spoiler
rubenwardy: you credit me for the screenshots of gimp's map, however I've only taken the last. The others are from gimp himself.