1. According to the operation you mentioned, you can indeed see changes in the minions, but it is a blurry BUG. Due to a program error, the minions turned into blocks that flickered like fragments. But that's it, there won't be any underwater levels. This rumor is because the Japanese version of Contra originally had a capacity of 256K, while the US version had a capacity of 128K, so some people thought that the extra 128K capacity was for no reason, and the number of levels would be doubled, which is why there were eight underwater levels. Rumors (plus the blurry screen BUG, ??because everyone didn’t have much game knowledge at the time, they suddenly saw this unconventional phenomenon and couldn’t explain it). In fact, the extra 128K capacity of the Japanese version is because it has an opening animation, and every level has a cutscene, and there are special features in the level (for example, the background of the fifth level is snowing). That's all.

I provide two versions for download. If you are interested, you can compare the differences I mentioned above

/download/2005/200508/8242.shtml

2. I have seen this pack before. It seems to have originally come from a strategy guide book called "Video Games Yidian" (earlier than Diansoft). There are many packs on it, many of which are very useful. But I don’t know why the author had a short-circuit in his brain and published such a fake intensive. At the same time, there was also a fake intensive with 255 people selected by Salamander (it was said that it was a two-player game and so on).

The concentration of Contra II and Salamander is either because the author encountered a game bug, or it was hearsay. Anyway, it is definitely not true. This is the same as the eight underwater levels of Contra 1. It was a rumor at that time. Consultation is underdeveloped, so people just spread rumors and fool a lot of people. Some people just follow the rumors and follow the nonsense. In fact, they have never practiced it at all.