This run aims to complete Sonic 3 & Knuckles as the character Knuckles, while also avoiding any use of the left and right buttons.
Game objectives
- Emulator used: Bizhawk 2.9.1
- Complete the game as fast as possible
- Optimize for In-Game Time (IGT)
- Minimize the use of the left and right buttons
NOTE: Bizhawk was used in order to skip the transition from Mushroom Hill to Flying Battery by resetting the game. This saves a couple of seconds over watching the cutscene.
Comments
Before I go into what happens in the run, I want to give a brief overview of the game and its physics.
Information about the Game
Sonic 3 & Knuckles (also known as S3&K) is one of the most popular Sonic games of all time. It is held in high regards as one of the best Sonic games by most people who have played it because of the story, gameplay, music, and level design. Sonic 3 & Knuckles is the result of plugging your Sonic the Hedgehog 3 cartridge and your Sonic & Knuckles cartridge together using Lock-On Technology. A quick little history lesson: Sonic 3 and Sonic & Knuckles were initially supposed to be released as one game, but due to deadlines the game had to be split into two. The first half of the game is known as Sonic 3 Standalone (or Sonic 3A), and was released on February 2nd, 1994. Sonic & Knuckles would be released later in the year on October 18th, 1994, which brought with it Lock-On Technology, which can be used with other Sega Genesis games:
- Putting Sonic the Hedgehog 3 on top of the Sonic & Knuckles cartridge will boot up Sonic 3 & Knuckles, which is a combination of Sonic 3 and Sonic & Knuckles, which introduces several new things, such as being able to play as Knuckles in Sonic 3 zones, and the addition of Hyper forms.
- Putting Sonic the Hedgehog 2 on top of Sonic & Knuckles will load a version of Sonic 2 called "Knuckles the Echidna in Sonic the Hedgehog 2," allowing you to play Sonic 2 as Knuckles, with all of his mechanics intact.
- Putting Sonic the Hedgehog 1 on top of Sonic & Knuckles will boot into a screen saying "No Way!" Inputting A, B, and C at the same time will allow you to play a game known as "Blue Sphere," which randomly generates blue sphere levels using premade chunks.
- Putting any other Sega Genesis game on top of Sonic & Knuckles will load a random blue sphere stage.
The game has three main characters to play as, all with unique abilities:
- Sonic is the fast cool blue dude, equipped with an Insta-Shield ability which can be used to hit bosses that are just out of reach, and avoid taking damage from several damage sources, like badniks and bosses.
- Tails has the ability to fly, and if you are playing as Sonic and Tails together, you can carry Sonic using the second controller.
- Knuckles has the ability to glide, climb walls, and break other walls that Sonic and Tails could not break. He also has a lower jump height than Sonic, making some paths in the levels Sonic-only.
What does minimum left/right inputs mean?
This restriction is what is usually called the "No Left or Right Challenge" or "beating the game without pressing left or right." The goal of the run is to beat the game while pressing left or right on the d-pad as few times as possible. Seeing as this is a 2D platformer, this seems near impossible, since you need to press left and right to... well, move left and right. However, we can use the other movement options presented to us to get around! Since Sonic and Tails aren't very diverse in their movesets, Knuckles is the best option for us to use. Now it is time to discuss the strategies I use throughout the run.
In most cases, gliding into a wall will allow you to climb up or down on it. Jumping off will turn you in the opposite direction of where you were facing. But if there is no wall that can be climbed nearby, use a ledge! If you stand near the edge of a platform, Knuckles will go into his balancing animation as he desperately holds on for dear life. However, it's not just a neat little animation. It also causes you to face the same direction as the ledge. This can be abused by landing right on the left edge of a platform to be able to turn left. If you end up facing left by the very left edge of the screen, you can glide against the left boundary to be able to turn right. This is not the case for the right side, however in certain cases, performing a frame perfect glide into a boss right next to the right boundary by abusing invulnerability frames can allow you to turn left without having to press left! But if there is no boss or enemy nearby that you can glide into, then you're stuck and have to die. You can sometimes also turn around on a slope by gliding right before landing on the ground. There is a variant of this with steep slopes that you can't normally ascend, where when you glide on specific points, it will automatically turn you around on the slope, allowing you to jump in the opposite direction. Sideways springs will change which direction you are facing as well. There is a trick when you're either stuck against a wall to the left that you cannot climb or if you want to save time, where if you glide within a few-frame window of landing, the game will automatically turn you to face right.
A trick known as "object phasing" is used quite a lot in order to save time in the run. Object phasing is done by standing somewhere with the object you want to phase through just offscreen, hitting the side of said object with a high amount of speed (the most simple method is with a 6-tap spindash), and then performing two 1-tap spindashes in quick succession. If done correctly, you will pass right through the object while it's offscreen. Objects that are offscreen are usually intangible and can be passed through as if they do not exist. Jumping at the right time when phasing through certain objects like moving platforms can also cause you to clip through collision, like through the floor or into a wall. This is more useful in a normal speedrun setting, however it can also be useful here in order to save time, like in Carnival Night.
There are a TON of areas where if you happen upon certain objects in the level, you will be stuck until either you reset, or the timer runs out. Here are some of the objects that you want to avoid:
Springs
Springs are not normally dangerous, however if you end up bouncing on a spring with no horizontal momentum and with no badniks that can hit you nearby, you'll be stuck there until the timer runs out. There are also places where hitting a spring will cause a chain reaction where if you do not react quickly, you will end up stuck on a spring bouncing up and down and up...
Fans
Fans that move you upwards, like the ones in Hydrocity Zone, are straight up (not straight down) no-goes. Like springs, if there is no method of gaining horizontal momentum before encountering the fans, then you will be stuck floating in the air above them.
Sandrises? Backwards sandfalls?
Whichever you choose to call them, they exist only in Sandopolis Zone, and they are dangerous to the run. Not only do they suck you upwards, they also can easily kill all of your horizontal movement. If you don't have enough speed to pass right through it, you will be stuck against the ceiling with no way out.
The main issue with these objects is if you end up stuck on or in them, you lose all control, save for left and right... which we can't use.
Noteworthy Moments:
Hydrocity Act 2
After the moving wall section, there is a part where you are supposed to ride some fans up to continue the level. However, there is one tiny little issue with that. While you are riding the fans, you cannot perform any actions besides moving left and right. And there is no other route past this, meaning we have to press left to get off of the fans... not! The trick I perform is, from what I have gathered by messing around with it, a very precise trick, involving landing on a specific part of the wall, jumping from a pixel perfect position, and gliding for exactly one frame within a one frame window. With good positioning, this will give me the speed necessary to just BARELY make it past the ledge! Hitting the side of the ledge, missing the frame perfect glide, jumping from the incorrect position, having glided onto the wrong part of the wall, or just having bad subpixels will all result in you being stuck against the wall still being carried by the fans. All you can do then is wait for the timer to run out.
Marble Garden Act 1
After destroying the first eye in the wall that I encounter, I perform a frame perfect glide onto the slope of the ledge, and it actually faces me right! This saves me having to traverse to the wall to the left and pick up a lightning shield.
Marble Garden Act 2
After the second Eggrobo intermission, there is a section where you need to escape an area where the ceiling is coming down to crush you. On the way to the boss, there is an eye in the wall that needs to be killed to open a door... to the left. Seeing as we enter the area facing right, it seems like we can just grab the wall and turn around that way. But unfortunately, the wall cannot be grabbed or climbed on, leaving us to our inevitable fate. However, we can still get past this area without needing to press left! Remember when I mentioned that you can turn around against the right edge of the screen using a boss or enemy? We can apply this same concept here using the eye in the wall. After getting the first hit in, I jump into the eye during its invulnerability frames, and do a frame perfect glide into the eye. This gets the second hit in, AND forces me to turn left. Now I can get the third hit in, and proceed on to the boss. This can also be done with the third hit, meaning you can have two chances at doing it. However, it is a very tight window, and missing it will result in you being stuck against the wall and being crushed to death. After making it past that section, I jump onto the steep slope, and by gliding on a very specific point on the slope, it will force me to face right! This allows me to get into the boss room without needing to press right.
Carnival Night Act 2
After getting to the section with some barrels and balloons, instead of waiting for the barrel in the tunnel to go up, I jump into the speed tube and glide to inbetween the third and fourth balloons. This allows me to object phase through the barrel, however now we have to perform a frame-perfect jump and a glide immediately afterwards. This allows us to get past the barrel without having to wait for it to go up enough to spindash underneath, saving several frames. If we don't do the jump perfectly, we'll either get pushed back to the left of the barrel, or we'll get crushed and die.
Launch Base Act 2
There is a part of the level where you need to hit a button to open the door to the flood section. The only issue is we need to climb a ledge to get up to the door, and the button is to the left of the door... and we're facing to the right. Since the door cannot be grabbed, we're kinda in a pickle here. But, of course, there is a solution! There are actually two, but one is easier than the other.
- Instead of climbing onto the edge and getting stuck, we want to climb as high as we possibly can, then glide towards the other wall to the left. Once landing, we need to glide back to the ledge. If you have the proper position, then instead of grabbing the wall, you will land on the ledge. Stopping your glide as soon as you land will allow you to balance on the ledge. Now that we are balancing, we can perform a full jump, and glide at the very peak of our jump towards the button. If we grab the wall, we can jump and quickly glide to either slide on the ledge or grab the wall, and we can carry onwards! This strategy is more forgiving than the other two, mostly because there is only one spot where you can really get stuck, therefore the trick is easy to retry over and over again.
- As we see in the run, we can perform the floor clip from the any% TAS without pressing left or right. All we need to do is perform an object phase into the flame shooter, (I was forced to wait due to the fire cycle) and then we can perform a frame-perfect jump when the spikes come out of the floor to be able to clip right through the ceiling, skipping the door altogether.
Mushroom Hill Act 1
At the first climbing section in the level, I perform a high glide using the mushroom badnik down below. However, when I cancel the glide, I turn to face the right! Did I press right to turn around?!! I did not! When I cancelled the glide with backwards momentum, it automatically turned me to face the direction I was headed. This saves time over having to climb the wall.
Mushroom Hill Act 2
haha monitor says no music for you
Flying Battery Act 1
At the boss, we can save 42 frames during the boss fight! By jumping right before the first attack, we can delay the boss from attacking again, and after he hits himself for the first time, he will attack again but much quicker than without the jump from before. We can repeat this twice and defeat the boss this way. This trick was recently found by BeninSweden, and you can watch a video of the trick here.
Sandopolis Act 1
We can perform a level wrap at the start of the level using the slope! By performing a 4-tap spindash into the bouncy balls, and being caught in the sandfall, we can get the right position to perform another 4-tap spindash and a frame perfect jump off of the slope to the right and we can clip into the slope on the left! This saves about a minute over playing the level normally.
Lava Reef Zone
About half a second was wasted in Act 2 due to bad cycles.
Other comments
This was inspired by a video from Gamechamp3000 about beating Sonic 3 & Knuckles without pressing right, where she had also set a bonus restriction of not being allowed to press left as well.
Thank you to BenInSweden for finding the faster Gapsule trick and showing me the wrap in Sando 1 was possible without left or right!
I think there are multiple parts that could be improved, however all of the levels that I see being improved might end up losing that time to platform cycles. That shouldn't stop anyone from trying!
For those that are curious: both the Chaos Emeralds and the Super Emeralds are impossible to obtain due to the Special Stages requiring the use of left and right, which is not allowed in this challenge.
Technical Information
Emulator Used:
- BizHawk 2.9.1
ROM Checksum
- SHA1: cfbf98c36c776677290a872547ac47c53d2761d6
eien86: Claiming for judging.
eien86: Replacing movie with one that improves it by more than a minute, submitted by the author https://tasvideos.org/UserFiles/Info/638564948057266943
eien86: Not much that I can add to the discussion. This movie is a fantastic demonstration of what having fun with TAS is all about. Beating a game while restraining oneself of an available inputs is always a challenge. This one removes not one, but two of the most essential ones: Left and Right. And it does so in through an exquisite execution.
Given this movie does not fit into any of the standard goals, I will categorize it as 'Alternative' class. I am also replacing the goal from 'Minimum L/R' to 'No L/R presses', as this movie reaches zero instances of either. Any improving movies will have to achieve the same number, but in fewer frames.
Accepting to Alternative
EZGames69: Processing...