Nemesis 2

Most probably best game ever for 1st generation MSX computers

This game was re-released in Japan as part of "Salamander Portable" (沙羅曼蛇 ポータブル) for the PSP. It runs the MSX version in an Emulator. You can choose between the original MSX version, or an Enhanced version. In Enhanced mode you get smooth scroll and they have updated the graphics.

A patch to enhance the game in various ways can be found here:
https://www.msx.org/news/software/en/gradius-2-enhancement-patch

Game play info in Japanese: http://www.geocities.jp/galfned/gura2/gura2.htm

It has one of the best soundtracks I've ever heard for a shoot'em'up. A great game, I'm curious about that Beta version Samor comments.

There's a beta version of this game that, aside from a large number of bugs and missing stages, also features an Egyptian level not found in the final version.