Completely ordinary time rift. A descent into madness

Before I talk about the rift in itself, let me answer the question that will be burning you the most during the playthrough :
There are precisely ||450|| checkpoints you have to go through before finally seeing the end (in spoiler because for the full experience, it might be better for you if you don't know how many there are)

I decided on a whim at 17 o clock to do this level entirely and my first advice is DON'T GO TO COMPLETE IT WITHOUT PREPARATION. You'll quickly realize the 8 hour time is no joke. And it's a really interesting experience.
At first you'll be like « oh but really how long can it be ? Certainly not THAT much, right ?
Then as time and checkpoints go by you'll start to notice the checkpoint count and that you're at the ninth one. Then the slow realisation that you're probably not even close to the actual beginning starts to creep, as your slow descent into madness

The level design never changes, the difficulty never changes either. It's not especially difficult by itself but the stages you'll go through will make this an olympic feat.
If you haven't given up already because you have your limits (and that's great), if you absolutely want to go through it all in the hope of finding this timepiece, then the suffering really starts. You go through dozens of checkpoint, in environments where it's very easy to take little shortcuts, so you think you might finish it quicker because of that, but what you don't know is the the timerift knows. It knows that you're taking little shortcuts, and it knows it won't actually save you. You're lost at its game of despair like a lost adventurer wandering through the abyss searching for a tunnel of light. The only way is up.
Very few words were left by other players and every time you see one, it'll be like encountering a human form in a wasteland. As you're traveling up the reaching the 50th checkpoint, you'll start thinking « oh, it's probably 100 checkpoints, then. That would make sense Come on, I'm nearly there », then as you slowly start to drift away from reality you'll enter a machine phase where youcombo several checkpoints at great speed, until you reach the 100th checkpoint... And realize it's not the end yet. So you'll keep on, hoping it'll be 200, but the a thought will start creeping in the back of your mind « what if the level was procedurally generated and it actually has no end ?... » even though the engine isn't really prepared for that, the fear creeps anyways. It doesn't care. At some point you'll start cutting the music to put your own sound on it to try and not go crazy and each time, you'll hope that the next hundred checkpoints will be the ones. As you drift into despair and madness, your mind enters a trance state so powerful you might not even be in this dimension anymore. You start to feel weak, your hands hurt, you can't even move correctly when you decide to take a break to get some lunch.
If you have to pull an all nighter for it (trust me, you might very well have to do it if you're determined), drink some tea or coffee when the morning arrives. You'll need it.
 And the at the top of it all, when you're almost there, thinking it'll probably be 500, the fear that it has no end will be so strong you'll maybe go see the comments under it to reassure yourself that it is real (if that's you, well then yes. There is an end. Carry on, you can do it) and then at the end of it all, you'll see the timepiece from afar at the last checkpoint and your face will lit up. You'll probably take a few photos (like I did), then suddenly the world world starts turning again as you're left a weak mass of accomplishement. You did it. It was completely exhausting, and you'll never do that again, but you did it. Congratulations, now you may rest.

This was a descent into madness and an ascension to enlightenment at the same time. I'm glad I got to experience this.
But I'm not playing this ever again

Oh, by the way, I said the 8 hour time is no joke. I didn't say it was accurate, though.
It took me approximately 18 hours to complete, pauses included. You might be faster, but know what you're getting into. It's really a psychedelic experience. And also, I can say you'll start to see platforms everywhere for some time afer. As I'm writing this, the text lines look like platforms, it's really trippy.

Now if you'll excuse me, I deserve some rest, especially for my hands