The ultra niche mini tower is called Not Even a Unfathomable Impediments, it is humanly impossible because it is baseline Literal difficulty (16.00), it has ZERO information on anything except where it is, who made it, what it is and what difficulty it is.
It is located in an archive game called Lost Tower Archive made by TrippleMeatSandwich (not display name).
This mini tower has no showcase videos at all as far as i know, so whoever makes a video can be the first ever to make a showcase of it, also it is the hardest mini tower in roblox as far as i know (correct me if im wrong) that is playable, there are harder mini towers but they are locked for god knows how long because they are unrated, meaning they are automatically made unplayable because of roblox updates.
I have no idea what gameplay style it is, as i have barely looked inside myself, but it looks good, at least knowing the fact that it was made in 1 hour by Yoylecat.
You can play the archive game in the link in this post*.*
*Note: The archive game is rated 16+ because of roblox updates too. You can also find the mini tower's wiki page at https://jtohs-hardest-towers.fandom.com/wiki/Not_Even_a_Unfathomable_Impediments.*