How to get through the customs when playing the Green Corps?

The enemies of the first level are mainly some small soldiers who don't know any special skills (hereinafter referred to as small soldiers), as well as several scud and weapon soldiers. The American version and the Japanese version are basically the same except for the number of weapons and soldiers. The second level of many games is more difficult than the first level, but it is also relatively simple. However, from the second level, the Green Corps encountered many difficulties. Besides attacking some enemies, it has to learn the skills of dodging. If you use the personal play of the first level to carry out the second level, it will end in failure to a large extent. There are many skills in this level, so players need to pay special attention. The difference between the American version and the Japanese version is that the Japanese version has a secret tunnel, which is easy to try, but difficult. The author thinks that the underground warfare of this level is relatively simple, and the US version has only one ground battlefield.