History YMMV / Valheim

** A later update introduced Growths, another Plains monster; they look and move like Blobs, but their attack is a shotgun/firehose-like hard to avoid blast of tar that not only poisons you but also severely slows you down, making you easy pickings for them or any other Plains enemy

** Fittingly, Bats in the Frost Caves. They are weak and die in one hit but are VERY numerous, attack in hit&run tactics, are only really attackable for a short moment during their attack, before they gain distance again and don't even drop anything useful. A fully equipped player will usually have to stand still, wait and methodically kill those pesky things for a minute while being in no real danger from their weak attacks. Most annoyingly, they do respawn after some time, so if a player dies in the cave, they can make recovering the equipment while naked a huge pain because they are so fast and hard to avoid.
*** Even worse is the "Stirred the Cauldron" raid, which is enabled by killing a bat. Think raids against ordinary enemies are annoying? Try defending a base where the enemies fly and any AoE attacks will do more damage to the surrounding structures than them.

** Anything that can poison you. Due to how health regeneration works, there is no quick method of replenishing health. Getting poisoned on low hp or when your food runs out can quickly seal your fate.
*** The gas cloud attacks of Blobs and Oozers are particularly nasty, as it's near instantaneous once executed and can't be blocked by any means. The poison inflicted by Oozers also has a high duration value.

** The mountains combine hard to survey terrain with many opportunities to die from fall-damage and some of the most annoying enemies in the game. Aside from the aforementioned [[DemonicSpiders Wolves]] and [[GoddamnedBats Drakes]], the [[MightyGlacier Golems]] are extremely sturdy and hard-hitting enemies that are basicaly immune to ranged attacks. This means they have to be fought close-up on difficult terrain while they destroy the landscape. Thanks to the cold and fast enemies, it is also rather difficult to recover lost equipment, especially during the very tedious boss battle against the flying dragon that loves destroying player bases. On top of that, the exclusive dungeons, the Frost Caves, are also much harder to discover than those in the Swamps or Black Forest.

** The "no-cost building" option added in Hildir's Request is just that, removing the resource cost from anything made with the hammer (food still requires ingredients). This makes buildings elaborate bases much easier since you don't have to go look for materials, safer since you don't risk trees falling on your head, and exploration is much faster since you can now create portals at will instead of hunting down fine wood and cores.

* ScrappyMechanic: Melee attack animations and hitboxes cannot be aimed and do not adjust their positions based on the relative positioning of enemies or the camera, making attacking targets on uneven terrain unreliable as your attacks tend to go over or under them. This can make melee combat against certain enemies or in certain biomes, such as fighting wolves in the mountains or anything in the Mistlands, very difficult and renders spears' melee attacks borderline unusable due to being nothing but high strikes that are unable to hit low targets at all.

* GoodBadBugs: The Abyssal Harpoon is a spear with rope attached to it, and it's main purpose is to [[YouWillNotEvadeMe pull enemies closer to you and prevent them from running away]]. But as {{WebVideo/SoundSmith}} [[https://www.youtube.com/watch?v=o8v7HCg-TRs figured out]], speared creatures build up force if they get stuck on something, which when they get unstuck will send them flying a short distance. And because players can be speared as well, and sitting in a chair counts as being "stuck", this exploit could be used to send players to ''the other side of the map'' in seconds.