Yeah, I was the one who suggested those (but didn't TAS them obviously). Here's the breakdown according to my understanding.
-Game is about collecting 'stars', with minor doors requiring so many stars to open. Major doors which are loading points require Keys, earned after defeating each Bowser boss battle.
-Backwards Long Jump glitch (BLJ). When using longjumps, you can steer Mario backwards, which when landing on a slope/staircase can enable another BLJ, whose speed will be added to the previous. This can be used in succession to reach incredible high speeds. This can be done to go through minor doors, but not the locked ones. This means the game can be done by glitching through all minor doors to get to Bowser battles, getting key, and then using that to unlock the next loaded area, IE next floor of the castle. The exception here being this one door.
-This door is supposed to require 30 stars to open, then when you get inside, mysteriously there's just yet another level entrance (Dire Dire Docks), making you think what the point was, and why was this one so special? But the neat thing is, once you complete the first star in that level, the DDD entrance portal itself moves backwards, revealing the TRUE reason why you're in here: There's a portal to Bowser #2 behind it. (See
23m52s).
So since pretty much everything can be glitched before/after, this was a heavy choke point to determine what was needed to finish the game, as different glitches required different set ups, and thus different amounts of stars to be collected.
-
70 stars. Intentional, 30 stars to get in, 1 star to shift portal, thus 31 stars to get to Bowser #2. Final door in game requires 70 stars.
-
16 stars. When you've collected 15 stars, MIPS the rabbit spawns in the basement. If you capture him, you get a star (ignored), but with proper positioning you can drop him through doors, taking him to this place, and jumping between him/wall to clip through this door. This negates needing 30, but since you still need DDD portal to be shifted, this route therefore requires 15+1=16 stars.
-
1 star. Finally after enough testing, the nearby small staircase could finally be used to to initiate BLJ, despite being perpendicular to where we needed it. With stalling/ricocheting off a nearby pillar it was finally enough to get through the door, requiring 0 to get in! Still need DDD shifting though, so grand total to finish game was 0+1=1 star.
-
0 stars, finally with enough precision the BLJ here could not only take Mario through the 30 star door, but still have enough speed left over to get through DDD too. Thus 0 stars needed to get to this place, as well as all the others. Final total to finish game, 0 stars.
Hence the shortened descriptions you'll find in the original post
here
