The swiming animation without water, is actually part of an unused power-up, where mario could fly, or part of the beta version where mario is in a cloud flying and using an actuall gun, since using an accutall gun is not for kid they went with fire flower to replace the concept of the gun. If you are swimming in actuall water you cannot open ? block and also cannot break bricks even as super mario, also you cannot stomp on land enemies, the game will crash if fire works happen underwater, so avoid the unit of time 1,3,6. Swimming in air that is the animation of flying, you can stomp on land enemies and you can break bricks if your Super mario or higher power-up you can open ? block.
The sky bonus in the dark that mario auto move this is a glitch world it is one of the world behond 8 in the original Super mario bros. since you can never get there normally, the reason it is doing that it just take random bit, it just make does level with garbage data, because that happen with the original super mario bros. in Japan when he switch the cartridge with Tennis and did not turn the console off, and only soft reset the game after moving in tenis so when he hit the continue code holding the jump button plus start it start in world behond 9 depending on how many step you take on Tennis, and when they made Super mario bros. 2 in Japan known for us as Super mario bros. The lost level world 9 was inspired by does glitch world, in world 9-3 in Super mario bros. the lost level if you take the vine or the demo cut scene ending pipe you go in the sky bonus with overworld element and that wall of smilly cloud, and the ending pipe of the demo cut seen stuck in between two wall is also a refrence to glitch world in the original super mario bros.
No does are not the lost level, levels. You got it so corrupted so it loaded a mirrored of 8-2 as world 1-1, the mirrored of 8-2 is either a level higher then 4 or a world higher then 8, this is why it is full of water, and since the same corruption is applied to world 1-2, it loaded the mirror of 4-3. In a horizontal level the level is repeated below and above, you can never see does repeat normally since you can't scroll the screen above and under but if you could you can see them, and if you scroll bellow the mirrored copy you see a bunch of random graphic that does not behave like they are suppose to, also call a glitchy wall, and if you scroll a really long time in the glitchy wall you will be at the top with the first mirror of the level
