Kojima Productions has a tendency to stuff Metal Gear re-releases with bonuses. Metal Gear Solid 3: Subsistence includes the MSX versions of Metal Gear and Metal Gear 2. Metal Gear Solid: HD Collection includes these extras, but the Snake vs. Monkey mini-game got cut out.
In Snake vs. Monkey, Snake has to use stun grenades to catch the mischievous monkeys from Sony’s Ape Escape series. Years ago I asked Metal Gear Solid creator how this collaboration came to be and it was because his kid is a fan of the Ape Escape games. Bummer, but considering Ape Escape is a Sony Computer Entertainment owned intellectual property and Metal Gear Solid HD Collection is multiplatform that may not come off as too much of a surprise.
Capcom and Konami partnered to add Monster Hunter missions to Metal Gear Solid: Peace Walker and in return Snake-wear for Monster Hunter Portable 3rd. We asked Konami America about this too and can confirm the Monster Hunter bonus missions will be in Metal Gear Solid: Peace Walker HD Edition, which is part of Metal Gear Solid HD Collection in North America and Europe. In Japan, the game will be sold separately.