i have some "underground"-thoughts already, concerning existing creatures:
(i'm used to play on "normal" difficulty)
-dragons & giant ants-
both DO NOT attack ballista (wooden arrow-tower) nor tesla. I could send you some savegame - but i think you'll believe me if i tell you that i can design my underground (ant-nests and open space above lava) a way to "farm XP" by placing these towers. For the dragons i also "farm" valuable armor, bones & meat by designing their area filled with not too dense placed weak towers (smallest tesla or wooden towers) and they have a chance to get adult. I think the older dragons give better loot.
So it was not a good idea in my eyes to re-implement the towers giving xp on kills but now it's probably too late to remove it again- so at least these creatures should not ignore the towers that attack them
the ants should move further away from theirs nest if the way is open and they should be able to pass open doors also. And they should "harvest" the plants/leaves in their caves, else they get overgrown and can not move any more.
dragons damage is hilarious small, i don't fear for my dwarves if they have to fight a dragon... the dragons should not have weapons nor armor in their loot but maybe some ores and dragons eggs if a use for them (see below doubling-bug)
-necromancing dark elves (portal-part keepers)-
they cast their fireballs in a way to high frequency for my feelings, and they should not be placed into a cave that has a brick-floor above lava. I don't even need to use a spell to get rid of him, just switch the brick-wall appearance and he's gone... what does he have that i can't craft? why should i bother fighting him? And why are they that strong (it's exaggerated, also their health) and why can they cast fireballs and hit dwarves through the wall even if door is closed again?
I would suggest to place all portal-part keepers into dungeons that have at least undestroyeable floor-blocks or to give recipe only if the keeper had contact with a dwarf. Their caves design & position of elve inside the cave should not be that random as currently- should work with undestroyeable blocks and doors here to shape the players path...
And if the keeper is not an undead himself- why does he not drown? I've made a lot of effort once to built him a nice "bath-tub", collected lots of water (it's a real hard job that should be rewarded...)
..and some more:
-doubling-bug-
sometimes it appears that items spawn twice: For example often there are two dragons eggs at one position
(at least after removing one egg and killing a dragon, but i don't know if it won't happen if no egg removed nor dragon killed yet, i did not purposely watch it)
- so this is a place for a high chance for the developers to find/check the reason for double-appearances.
(not that bad - but please add a use for these dragon eggs-
i think of a "dragon skin potion/dragon egg-meal", (see below pitcher) similar duration to beer, serveable on a table as food, that gives a 33 or 66% (fireball?)-resistance to dwarves maybe add some glow-effect to the dwarves then or display some additional heart(s)- that would equalize the fireballs frequency of the keeper and could reduce dragons damage - but the dragons damage could be 3 or 4 times the current and not just blow the dwarves through the area )
also doubling very often the goblins-camp-drops, seems to affect also the amount of appearing goblins: i had that quadrupled already multiple times.
***
btw, goblins camp:
what am i supposed to do with 3 large kitchen stoves at once, 3 smithys and 9 comfort beds? I disassemble all that stuff...
Anyway i think the LOOT from goblins camp is way to OVERPOWERED. Awaiting the goblins is like abusing the infinite chest-loot-bug the game had previous versions 0.9.0.13.
I got my "true dwarf"-achievement (200 gold-ore) by disassembling the loot (yatagans & golden helmets they always have) and maybe digging 20 pieces of gold myself... I never need to craft any elevator, neither diving helmets nor fishing rods.
For this i would suggest: a medium kitchen stove would be enough, so i have a reason to craft the large ones by myself additional to those i find in some tombs... - maybe a mill, workbench, smithy etc. ONCE but not that masses of valuable finished/already crafted stuff and predicteable the same.
remove santas jacket and the fifth portal part from the camps drops please.
The camp should drop MUCH MORE RANDOMIZED and also cheap raw materials as coal, ingots, boards, oil or simple items as barrels, bottles, buckets, ladders, food, cheap & later also better tools (axes, pickaxes) etc. Why should goblins have mithril armor- and not wear it? does not fit in size? They have Yatagan and attack me with a wooden spear? makes no sense.
Perfect were the camps drop items (value|count) depending on players level.
+ if dwarves equipped with goblins spear they have 2 different attacking-animations but if one of them (i don't remember if up/down or left-right) is played they make no damage +
The goblins shaman: why does he not fight back? I would await him to be the hardest of them that protects the camp and to use some magic (sparks or fireballs?)
***
Oh yes, i forgot, something:
-equipping potions-
i would like to check potions in equip-menu for dwarves equipped with a staff as the arrows for dwarves equipped with a bow so a dwarf needs my OK to use a potion and i can prevent them for example from casting the beholders into snails ( i need the beholders eye for new snail-potion

)
-items falling onto hatches/ overgrown background-blocks to mine-
odd behaviour in both cases: if an item drops onto a hatch (i think only happens if closed and i think it happens on other doors too) or if a background block gets marked to mine and the block gets overgrown by leaves in the meantime. Then dwarf comes, mines the background, leaves disappear and mined resource-drop is placed block-centered - you have to look at it, i can't describe, both looks weird.
-price for heavy bow/ mithril-staff in the shop-
the heavy bow at 15 gold is a real bargain (2 bars of mithril-ingot cost already 20) so 30 gold would be adequate for this powerful thing.
the mithril-staff at 35 is a little too expensive compared to the bows power but it has more reach, so concerning this and the needed resources i think both should cost 30.
-silver arrows-
silver is more rare than gold in the game since there's no earth-layer that drops random gold plus the much gold the goblins bring into the game. So crafting silver arrows from silver-ingots is way to expensive and one does it only once to proceed in campaign mode.
Simple silver were expensive enough - or add some random silver-drops in the sand-coal-earth-layers. Also iron/steel arrows instead (there's enough of iron since skeletons drop metal gear that one can disassemble) were thinkeable
-pitcher-
also found in goblins camp...
what is it used for? Its not required to craft anything else from it as far as i know. Does every dwarf need one? how can i give it to them then? Is it supposed to be placed onto a table? What do i put inside? Dragon-eggs liquid? Put an egg into 3 pitchers to get 3 meals... just raise the amount of at once crafted pitchers.
-paper-
what else is it used then for crafting pictures?
i imagine to have some dwarf that goes to a desk (like a lab) and writing something onto it. Needs paper, color, a feather and some magical mushroom, spider-web, brain, bone, slime or crystal depending on spell. This could be an alternative way for magic without the use of players mana-points. Like i can craft for example "summon imps"-scroll (make it craft a few at once as the potions) and cast it once (so the scroll disappears but no mana used)
-tesla-tower deconstruction-
if i remove some already placed level 3-tesla tower completely thereafter i get only the resouces for a level 2-tesla so i suspect the top-tesla does not drop the resources
-towers on bridges/towers falling-
if placing tesla/ballista onto wooden/stone bridges (not logbridge) the tower should not fall while changing bridge-layout. Maybe only fall if quickslot that contains currently the bridge-icon is not active any more or no more bridge in quickbar at all to prevent them from accidently falling.
if placing towers above any item onto any bridge (i can for sure say this about stockpiles and tower on logbridge above) and thereafter remove the bridge then the tower and the stockpile "share" the block - so they are both a this position- is purpose? Perhaps better to "lock" a block as long as some tower is placed onto, so they can not be removed (as the earth is locked where some tree grows or where some pillar is placed onto)
-campaign tutorial quest idea-
as the quests like "dig a tunnel" etc there could be also some "shape your environment and place earth, sand or stones" where the player has to place at least one foreground and one background-block of any of the 3. I can remember when i played the first time (v 0.9.0.04) that i was fascinated by that little dwarf hunting snails and digging tunnels but i had no idea that i can place simple stone or dirt to build, and not just the crafted objects.
-readability-
goes to your GUI-artists:
please change the fonts appearance of portal-spell-timer and in crafting menu, the items-count:
Either outline or shade the font so one can always read it, no matter what background-color there.
sorry for that much to read, i hope you have the time and i guess i should have added this to the other thread.