How is this speedrun possible? The Legend of Zelda World Record Speedrun Explained

Watch the unedited run here: (27:57) The Legend of Zelda any% no u...
Patreon: Patreon: bismuth9
Twitch: Twitch: bismuth9
Twitter: Twitter: Bismuthi
Discord: Discord: discord

Chapters:
00:00 - Introduction, layout, category
02:30 - Screen scroll, Level 3 manipulation
09:33 - Level 3
15:52 - Level 4, Item drop manipulation
23:25 - Level 1
29:40 - Level 2, Rupee route
33:45 - Level 5, Enemy movement, Recorder
44:55 - Level 7, World wrap, Roocorder
52:30 - Level 6
56:25 - Level 8
59:40 - Level 9, Conclusion

Thanks to my Patreon supporters:
Mittenz
Kosmic
rictic
Znernicus
Tuo Padre
NOtoHOUtoSEAtoDENtoPA
vivas5
Kevin Nix
Jacher
KingParity
Punchmaster
Skyehoppers
Billy Hansen
Veegie
Tungul
MrValdez
Martin Berrum
Billy Floyd
Francisco Beltran
Drew
CatCube
Alexander Roper
Mark S.
Curtis Fraley
GTAce99
Dylan Sinnott
Riku
Jeremy Marquis
William Tryon
Shaheen Ghiassy
Robert Smith
Amanda Knipfing
Cosmicabuse
Nylaryx
Sophia Blue
Mime
Avi Finkel
Hanjun Yang
Shelby Coulter