Nemesis 2 actually is two games in one. In the same cartridge there is Nemesis 2 (international version), and Gradius 2 (japanese version). The opening of Gradius 2 is has a lot more text than Nemesis 2, so it made sense to make a translation more complete than the official one.
Also, the manual of Gradius 2 has a page telling about a contest for Gradius 2 players, I've translated that as well.
Web: Gradius 2 (pt-br)