A short-ish, retro-ish, unforgiving-ish platformer-ish" is genuinely one of the most charming game descriptions in the jam — the self-awareness is refreshing! NicholasYZ's observation about the jump speed being calculated from a snapshot of movement before the jump is a really interesting technical detail, and the point that it leaves room for satisfaction when you master it shows there's depth in the mechanic even if it's punishing at first. yobitjoy1's note about the light and dark platform distinction having different roles is a nice design touch that rewards players who pay attention. Bringing the platform gaps slightly closer and lowering the jump audio volume like NicholasYZ suggested would go a long way toward making the difficulty feel fair rather than overwhelming. Submitted 15 hours before the deadline too — solid work under pressure!

Feel free to check out my sky platformer too if you get a moment!

Maybe i have a skill issue, but its quite difficult (other comments seem to be suggesting the same thing so prob not on me). Perhaps the goal was a rage inducing challenge, but i fell back to the start on the one jump quite a lot. 
I enjoyed the sound effects

I also made a climbing game, but in a very different way, if you'd so gratiously play it

It is really hard to play. to far apartaretheplatforms.but i liked thelight and dark colorsplatforms,each has a difrent role

It's a hard platformer as the speed calculation is abit funky, it seems the jump speed calculation is based on a snapshot of the movement right before the jump which can make estimation of jump distances really hard. However it may be done intentionally to make the game harder but it leaves room for satisfaction when controlling the character. The jump audio can also be lowered as it is quite sharp. All in all, its a working game so congratulations!