Most of the achievements are tied to the plot and can't be missed while advancing in the game.
Hovewer, as some are missable, and one may require replaying a big portion of the game, it's best to look at the missable section first if you want to avoid replaying the game.

I'm doing the guide from my memory after finishing the game.
Feel free to tell me if there is any mistake.

One advice - be careful with filling a bucket as you need it for both coal and water, so just fill it when needed. Coal will be needed twice, water once IIRC.

This one is only for achievements and not a walkthrough.
Also, obviously, spoilers.

After leaving the city and before going to any dungeon, talk to the Lumberjack.
Depending on the options you pick, he will either stay there and no longer wish to talk to you or he'll be gone and you get his axe.
The outcome here decides your first weapon in the game, if you won't get the axe you can find a club in the dungeon (if you get the axe the club is gone)
Hovewer, you need to get the axe here to be able to get the achievement. If you get the club from the dungeon first, the Lumberjack is gone and you can't talk to him.



It seems you need to get to the option to say "THE CITY GATES WILL CLOSE FOREVER, NOBODY CAN GET IN FROM THE OUTSIDE..." to get the axe.

Example dialogue choices to get it are:
• 311313
  
• 322223
  
• 332223

The alternate 4th dialogue options (311 route):


I only managed to get it when starting with the 3rd option but it would take too long to check all possible combinations so i only checked a few and it's very possible there is more.

If you want to try by yourself simply save before talking and load if you don't get the axe.




Later in the game when you get enough gold, you need to go to the blacksmith and instead of buying different weapon, sharpen the axe.




Give the beggar with child a metal coin.


Drink some wine, it can be found in dungeons or bought. It has a healing effect.


At the inn from the begining, there is a guy you can play 3 cups with. Win 5 times.
Just follow the cup with the coin.
You can save before each try and load if you fail so you won't lose coins.
At some point he will refuse to play with you so the money is not infinite.





Drink the water from the cave spring. Since it's healing you have to go there with your health not full.

Achievements you don't really need to think about while playing.
Most are self explanatory.


Fill a tankard with beer.


Finish your tasks in the inn and talk to the owner.


Give a coin to the bagpiper.
You can do it anytime just for the achievement but at a specific point in the game you will have to do it to advance the plot anyway (so you will have to pay him twice if you do that before).


Ask the guard to open the gate.
Wake him up my throwing a cabbage at him.
Can be found in a smelly barrel near.
Barrel can be opened with a bent bar that can be found near the blacksmith


Find the dead horse outside the city after you get the rope.


Rewarded for killing first thing in a dungeon.


Technically, it could be missable but not sure if it would even be possible to pass the game without blocking even once.
You block with right mouse button after you get the shield.




Change the cart route in the dungeon by using the lever.



Find 3 puffballs in the dungeon.








Find the smaller key, it's in a drawer.


Make the soup to get the pickaxe.





Mine the gold ore.







Search through the tavern stash.

Only 2 times you get an item.









Make the gold coins from the ore.


Buy the helmet from the blacksmith and examine it.


Tear down the wall with a pickaxe.
(You need to hit in specific places, you will hear when it works and then when that fragment collapse look for the next one and so on)







Make the barrel near the bars explode to open the passage.







Get the key from the coffin in the sunken part of a dungeon.

There are two endings and to get both just do a save before talking to the old hag after getting the book.



Pick "YES, IF I AM THE CHOSEN ONE, I WILL FOLLOW MY DESTINY!".
Give her the book.



Pick "NO! LET THE BURNING FLAMES CONSUME ME, IF IT"S ALL TRUE!"
Go back to the city.

Walkthrough[lparchive.org]
A walkthrough (for the old version). Useful but does not mention the axe (i think). Good if you just want to move further and are stuck but may require to look around it a little as the game is a little open about the order you do things so it may different than theirs.

Also, when i compared the solution to draining the sunken dungeon is different.

"Proper weapon" achievement?
Discussion about the axe with solution. Thanks!