Hideo Kojima has confirmed on his English twitter account that Metal Gear Solid HD Collection (check out some comparison screens in the slideshow to the left of this article) will include the two more games, Metal Gear and Metal Gear 2: Solid Snake. Originally released for the MSX, these two classic titles were a part of the Metal Gear Solid 3: Subsistence re-release.
Hideo Kojima also revealed the differences between the domestic (Japanese) and overseas (western) releases. The Japanese version will include a product code for Metal Gear Solid but won’t include Metal Gear Solid: Peace Walker while the opposite holds true for the western release. Finally, Kojima added that Metal Gear Solid 2 in the Metal Gear Solid HD Collection is based on the Substance version. The Japanese version will have Japanese voice acting. You can check out his statements below:
Metal Gear HD series. The domestic version is a package of MGS2 and MGS3. But, there is also a product code for MGS1, and MGS3 is subsistence specification, so MG1 and MG2 which were sold on MSX are included. This means, you can enjoy MG1, MG2, MGS1, MGS2 and MGS3 with this one!
Metal Gear HD series. Overseas edition is a package of MGS2, MGS3 and PW. There is no product code for MGS1, but since MGS3 is subsistence specification, there are MG1 and MG2 which were sold on MSX. For this, you can enjoy MG1, MG2, MGS2, MGS3 and PW with this one!
MGS2 HD is based on subsistence, but the sound for the domestic version is of course in Japanese. There are many questions about this.
The upcoming Metal Gear Solid HD Collection includes enhanced remastered ports of Metal Gear Solid 2: Substance, Metal Gear Solid 3: Subsistence and Metal Gear Solid: Peace Walker. Once again, you can check out some comparison screens (old shots are posted first, followed by the high-definition ones) in the slideshow to the left of this article.