This is a TAS of FDS Super Mario Bros. 2, specifically intending to complete the game warpless without pressing B. The only way this is possible is by playing through the letter worlds, which are a set of 4 secret worlds that are unlocked by pressing A+Start on the title screen after getting 8 stars. This is because the regular level set is impossible to complete walkathon, with or without warps.

Because getting 8 stars is required before being able to play the movie, that means this TAS starts with an unclean SRAM state. This means a verification movie is required, which can be found here: https://tasvideos.org/UserFiles/Info/638008645247617084 The linked movie gets the required SRAM state this TAS uses to start directly in A-1.

Flag Despawn: Used in A-3. If all 6 slots are filled by the time the star flag--the one that raises up after the timer countdown sequence has completed after each flagpole level--loads in, it will be forced to load in the special slot, which the flag normally is supposed to occupy, causing it to disappear. This ends up causing an effect similar to Flagpole Glitch (FPG).

Full Flagpole Glitch (FFPG): Used in A-1 and D-1. By touching the flagpole as low as possible--either by clipping in the ground as seen in this TAS, or by using an enemy bounce like in 8-2 of SMB1--Luigi is too low to snap on top of the flagpole block, causing him to be ejected out to the left instead. This causes the timer countdown to begin earlier than is otherwise possible, which can save a large amount of time.

Wrong Warp: Used in C-1. In the SMB1 engine, the game can only store one area pointer at a time, so if you enter a pipe or climb a vine before its intended waypoint is loaded in, it will send you to the area previously in memory, or it can be reversed, where you load in a new way point before doubling back. In this case, the area pointer is left at a very large value from the warpzone pipe at the end of B-4, and since upside down pipes were never intended to be enterable, there is no update before the first upside down pipe in C-1, which ends up letting Luigi effectively skip the entire level.

Damage Boost: Used in D-4. If Luigi has collected a powerup, and there's no other way to get past an obstacle/the only other way is extremely slow, it can be better to just take the hit and damage boost through. As far as I can tell, this is the case for the long firebar at the beginning of D-4.

Wall Clip: Used in A-1, B-2, B-4, C-1, and C-4. There are multiple different ways of clipping through walls, the one most often applicable to walkathon is the corner clip--to help create the feeling of smoother motion throughout levels, the game will only stop Luigi when his vertical speed reaches 0. If you abuse this to start falling as high as possible while not landing on top of the block, and press left on the frame Luigi is stopped, he can be pulled all the way into a block, rather than be pushed out of it as is normal. The amount of airtime Luigi has before landing inside the wall will affect how far he goes inside, as the longer he spends in the air, the farther to the right he will be pulled, which is important due to the fact that the moment Luigi lands, if he isn't fully clipped into the wall, he will be pushed out to the left instead.

In B-4 and C-4, a big Luigi-only type of clip can be done called a crouch clip--by doing a crouch jump, and hitting the walljump pixel immediately below a ceiling, Luigi will uncrouch the frame he lands, which causes his head to end up inside the wall, instantly making him fully clipped inside. In C-1, the presence of a ceiling above the upside down pipe means that even though Luigi cannot do a crouch clip, he is still able to jump a few extra times to fully clip in. Note that a blazit clip, like the one seen in 5-2 in the warps TAS, is not possible walkathon, as you must be 3 pixels inside a wall to perform it, and with just 24 speed, Luigi is never able to move 3 pixels in a single frame without wind.

Speaking of wind, in D-1 wind is used for a type of wall clip unique to SMB2J, where by keeping a small amount of leftward speed, wind is able to push Luigi far enough inside the wall for him to do a jump and clip in all the way.

Lastly, B-2 has a rather unique type of clip that is only seen in water levels, and is only possible with big Luigi. If Luigi has upward speed into the bottom corner of a row of blocks at the very top of the screen, his head simply has no collision, and it allows you to fully clip in while carrying maximum speed, allowing for a very speedy path through the coral section, though not fast enough to save an extra framerule. Here it's simply done for entertainment purposes.

Walljump: Used in C-3 and D-4. By landing right at the spot where two blocks meet in a wall, Luigi can actually clip just far enough inside to land on the lower block for 1 frame, which usually is only useful for the fact that it allows you to jump in that 1 frame window, as seen in D-4, or famously in 8-4 in SMB1. However, here, it ends up being useful in C-3 as well, as it both allows Luigi to have a lower maximum height on the green spring jumps, and instantly slows him down to 0 speed. This is necessary because you actually have to land on most of the green springs, which generally ends up requiring a lot of slowing down.

I didn't intend to make another submission so quickly, and have a repeat of what happened with my A-D Mario warps TAS, but I discovered in the week following my previous submission that there was a way to save a lot of extra time in C-2. In that level, a blooper must be lured very far to the right, so Luigi can use it to cross a normally uncrossable gap. There are two types of bloopers in this game, one that hones in on the player's current position, and another that travels in the direction of the player's last movement. This TAS uses the latter type, as the former cannot end up to the right or left of the player enough to be bounced off.

In my previous submission, I had let the blooper descend all the way to where Luigi was near the bottom of the screen, and I found out that this was actually very bad. The type of blooper being lured here will always descend to where the player is before continuing its direction of travel, which means the most optimal strategy, and thus the one this TAS uses, is to jump at the exact right moments so that the blooper always detects that it's at the same height as Luigi, allowing it to continue moving right. This saves 00:02.795 in C-2 alone.

Unfortunately, due to the different RNG values, I ended up needing to lose 00:00.017 in D-4 over my previous submission, which yields a net time gain of 00:02.779.

nymx: Claiming for judging.

nymx: Renaming the goal to fit more appropriately.

nymx: Okay… it’s been so long since I’ve started this game from scratch that I completely forgot that the “Letter” worlds unlock this way. I’m glad I finally realized that!

I also synced this using a different version, since the submitted ROM didn’t match the one I was able to find. Everything checks out now, so that’s good as well.

As for the run itself, I remember having a discussion years ago about “walkathons” and whether they were boring. I quickly learned just how popular they are and how much people genuinely enjoy them. This was my first time judging one, and now I can honestly say… I get it.

I thought this was a really strong effort that showcases the concept extremely well. At first, I wasn’t sure whether a “Letter” world run could even be completed in this style, but strategies like the one used in C-2 clearly prove that it can.

Also, thanks to CoolHandMike for your thoughts.

Accepting as a new branch of "Worlds A-D, warpless, Luigi, walkathon", to the Alternative classification.

fsvgm777: Processing.