i have been attempt to recreate this for a while, been looking at runs etc, but i can not seem to do any of the strategies i see. Am i missing something, i know most of the tech that i see i just cant get it. any help apprecaited :)

Ive just beat all my friends time on ultrakill and I just got the game like last week, but its awesome and now I want to start beating times on here, whats the best guide to get started on, rn I want to do full game but if theres a big doc or something with every level on it that would also be helpful, ive been scowering around and i've found a few useful things but most are outdated. 