What I would personally like to see:

* More Black Metal weapon/tool availability.
* New tier of weapons, tools, and armor (or two or three) for Mistlands specifically.
* New unique items such as Frostner, Porcupine, and Draugr Fang.
* New unique enemies, which I know are already coming. I do like surprises, though.
* Normalization of food durations, with a change to when decay starts happening.

* Possibly the addition of weapon-related bonuses added to existing armor sets. Example would be: Troll Leather set already offers a Sneak bonus; if you use a dagger, give it a critical damage multiplier buff. If you use a sword, hammer, etc. give them a different buff.

* Possibly a more fleshed out skill system, which allowed for use of particular combat-related weapon skills. In other words, a bit more on the RPG-element side of things.

* Possibly the introduction of "Legendary" crafted items. We already have Flametal, but it has no use aside from being able to be turned to Ingots. I theorize that perhaps this will be used for a Flame-based two-handed sword, similar to what Surtur uses in the mythos. Obviously we wouldn't be crafting THAT weapon, but a "replica" so to speak.

* Upgrade for the Hammer and Hoe that allows for QoL-related changes, such as mass planting/harvesting, and lower Stamina costs when building/repairing. (Think of grid-based planting, assuming you have the seeds on-hand. For the Hammer, how about a mass-repair option?)

* Some sort of procedurally-generated rogue-like dungeon with unique rewards.. although something like this could be an update in and of itself, and as of right now we lack a gameplay loop to warrant such a system. This is mostly me thinking of long-term enjoyment aside from building.

And, obviously, I'd like to see massive improvements with the Engine itself that allowed for better performance all around. I enjoy the graphics as they are, but we all know what starts happening when your structures contain too many entities. I'd like to see this issue alleviated entirely, however I'm afraid limitations with Unity keep it from happening.

Best case scenario, in a perfect world, I'd absolutely love to see Valheim using its own Engine, which got rid of the limitations it currently has under Unity. However, I also know such a thing would require all current and future development for the game to halt indefinitely, and even longer to port it in.

So, if there was ever a "Valheim 2", I would absolutely want IGS to build their own Engine for it. With such an updated Engine, we could have things like tunnel building, less terraforming restrictions, and likely better performance over all.

But anyway.