Explorator mode
This is hardly a missable as it can be at any point by just AFKing in the shadows for a minute.
Shadowbathing Stayed in the shadow for a minute straightThis is another easy achievement to get at any time, I don’t suggest doing this during your Shadow master run.
Deadly sunburn Stayed in the sun for too longClimb up the stairs to get the candy

Sweet miracle Get the chocolate candyAt the blue van, turn left, on top of the red barrel, pick up the inhaler.

Plastic relic Get the inhalerDuring the night breaks between chapter 1-2 and chapter 2-3, go to the front of the truck to show your Mom one of your collectibles.
Mom, look! You showed your mom something you foundInside the green tent, pick up the magazine.
Archive from the past Get the magazineInside the white tent, pick up the weird plushie.

Weird fluffy thing Get the weird plushWhen chasing the dog inside the warehouse, turn a corner to find the toilet paper in the shopping cart

Golden roll Get the toilet paperYou’ll soon find the dog, from now on you can pet him 5 times with “E” and throw the ball with “Space.
Who’s a good boy? Pet the dog
Who’s a REALLY good boy?! Pet the dog 5 times
Fetch! Play with the dogClimb up on the shelf from the right, pick up the puck.
A memory of dad Get the puckHard to miss, pick up the chalk before going down the ladder.

Colorful dryness Get the chalkYou’ll now have all the collectibles.
Hoarder Get all collectiblesSurvivor mode
Before starting this run, to ensure getting Shadow master, it’s recommended to delete the save files at C:\Users\%username%\AppData\Local\Helpless\Saved -thanks Therzuzada!
This isn’t a hard achievement, take your time to move between shadows and it’s easily doable. This achievement only unlocks on the Survivor mode.
Shadow master Complete the game without dyingThanks to FrozenShiver for his great guide, all credit to his effort. you can also read the original guide from Steam Community. enjoy the game.