Alright, a bit of feedback from me.
As stated previously, as much as new features are great and I am really excited for the myth arc, bugfixing also needs to be given priority.
Fort Mode
-Feels like a cap on migration wave size would be helpful. Maybe with a default of ten ? I'm a fairly experienced player, been playing since 40d (though intermittently) and I still have trouble with huge migration waves. A new player's frustration could be bigger.
-Getting your dwarves to equip armor properly is still broken and quite frustrating even as an experienced player. It's either no clothing and armor only, or a mishmash of armor and clothing that doesn't really protect much.
-Marksdwarves are basically completely useless right now unless you restrict their pathing because their AI is suicidal and counterintuitive. Also there are still ammo equip bugs that cause trouble.
-Every military dwarf is basically on Leeroy Jenkins mode right now. They don't understand "station". They will throw themselves at threats that overpower them (and die) simply because they were first on the scene. Some basic AI tactics (Aggressive, Neutral, Defensive or such, like in most RTS games) would help.
-A better ingame tutorial. Right now, the game has completely outgrown the ingame tutorial.
-Better UI for building walls and such. It's quite repetitive after some time when you're making walls or towers. Letting mouse "paint" walls or even other building designations would be nice.
-Some better filters for embarking on a fort. Separate ores in weapons-grade, precious metals and other metals, maybe ? Or by different types of rock layers as suggested. Though the issue is that newbies won't make the difference between those without some explanation.
-Conflict bugs needs to be fixed. When there is a major fight going on and dwarves die, the rest of the fortress will cancel what they're doing and attack the hostiles en masse - even if they are civilians, or even if it should be a really bad idea. This can kill a fortress pretty badly. Almost killed one of mine lately.
Adventure Mode
-Adventure mode's discussion options may be a bit too overwhelming for a newbie. I know they were for me. Maybe put in some more menus ?
-Being in an area with people means a lot of discussion spam, and not only it is distracting in general, but it's somewhat annoying to follow a discussion you are having with a single NPC through lots of other unrelated discussion.
-It feels like rivers freeze too often and/or too quickly. I did lost one adventurer to being encased in ice by swimming in a river. Also, it would be helpful to be able to gather ice from a frozen river to melt with a campfire (like you can do with snow). When I'm outside in the wilds, I'm not sure where to go to find an unfrozen river to drink from.