Vs. Super Mario Bros. is basically a combined version of SMB1 and SMB2J. There are many differences though, but the techniques used for speedrunning are generally the same. The main difference lies in the fact that you cannot hold L+R (similar to the real-time speedrunning in SMB1), which makes the vine glitch unusable and also reduces the effectiveness of fast acceleration.
This TAS is almost 20 seconds faster than the current publication and also 715 frames faster than another submission currently (their timing ends differently, and this is the aligned result). In terms of entertainment value, I did my best to collect more coins and kill more enemies. Here are some details about the levels:
1-3: Optimized the mushroom catching, enabling Mario to reach the running speed, saved a few frames.
1-4: Due to the change in the position of the fireflower, it is much more difficult to catch it than in SMB1. Perhaps there are still ways to improve it.
2-1: The ground has changed, so the techniques in SMB1 cannot be used. The situation in 3-2 is similar. In 3-1, 6-2, and 7-1, it was due to the changes of enemies.
2-3: Clipping into the ground through a cheep-cheep. This was probably the most challenging part of the entire TAS. It took me a lot of time. Fortunately, I didn't need to do it again in 7-3.
2-4: Due to bad luck, I have to slow down at a firebar.
5-1: Only when perfectly accurate bullet is available will BBG be able to save time. This is extremely difficult, especially since I haven't yet understood the random process of the bullets. I made numerous attempts but still failed to complete it.
6-4: The two frames of lagging seem to be unavoidable, one for lots of firebars and the other for Bowser battle.
8-2: Similar to SMB1, BBG can save 42 frames.
8-4: Except for the last room, almost all the others are already perfect because they are the same as SMB1 and have been optimized very well. In Bowser's room, due to the additional bricks above, I have to find the right pattern to pass through. Eventually, I chose to kill Bowser with fireballs, but this would also waste 1 frame.
Overall, this TAS was done rather hastily, taking only one week. Some levels still need further testing (such as 5-1), but I believe it is enough to replace the current submission. Additionally, I have noticed that the physical characteristics and frame rules of this version seem to be different from those of SMB1, which need further research. At last, thank you for watching.