I would suggest you use a keyboard when playing this game instead of a controller.

'G' puts the game into first person, which makes much of the game easier.
'Space bar' is jump.
'Shift' to run.

If you go into first person in the blue and black flashing level, the flashing is not as bad. It still flashes a bit, but it's no where near as bad as in third person.

Unskippable Achievements:
Release:

This achievement is gotten just by finishing the game, it's not skippable.

Skippable Achievements:
Too Close!:

This one is gotten in the level with the pink skull trying to kill you, you will most likely get this achievement accidentally, by running into him. You just have to run into him, and kill yourself to get the achievement.

"I Wonder How It Is Down There":

In the level when you collect the keys, if you jump off the edge, you get this achievement.

Where Do I Go?!:

To get this one you'll need to just be in the maze level for 20 minutes.

I know that I made one wrong turn at the end, but otherwise, I made all the turns correctly.

https://youtu.be/m4AXNENBWV4

I was able to do all the achievements without help, except for one, which I looked up. I needed help with the 'Where Do I Go?!' achievement, which turned out wasn't that hard. I got help for it from the Steam discussions:
https://sp.zhabite.com/app/862580/discussions/0/1728701877460938120/

The rest of the achievements I was able to get myself, without hints or help. I didn't need help with the maze either. And I didn't need a walkthrough. The image I used for the thumbnail was a cropped image from my playthrough of the game. I did mention the discussion's way of getting some other achievements, such as the jumping into the void one, but I got that one before I read about it.

The video I attached was one I recorded myself.