Yep, Metal Gear Solid V it is. :-)
Your turn.

It will be super easy:
Im the Mighty Pirate™ on funny quest to cure bad voodoo disease which spread all over the nearby islands.

Pretty sure it's - Monkey Island 2: LeChuck's Revenge...

Actually its from Tales of Monkey Island, but this is the same game series, so its your turn now. ;)

Cheers!

The world has been torn to pieces by a doomsday machine, used at the culmination of a bitter war between two nations. As one of the few survivors left, I'm on a mission to heal the world, but in the process I discover that the story is not as simple as it seems, and the survivors who've joined me harbour secrets that determine whether the world can be healed... or whether it should be healed at all.

OK... can you describe those survivors a bit? Are they all human?

Yup, all human. Only those two nations are relevant to the story and characters.

Sorry, I've been AFK. The game I was describing is Bastion.

In the interests of moving the game on - open floor!

I beat Bastion long ago, but I'd swear the war thing is revealed way before the 3/4 point. So you either didn't get that far into the game or you've got a lousy memory. :P

I just checked a video and I got about halfway through, I stopped playing after the boss fight with the Anklegator. Was it mentioned before or after that? I usually remember stories very well, that's why I'm surprised I don't remember the war- maybe it was mentioned briefly when you find Zulf and I forgot it because it seemed not that much important at the time? It does sound kind of familiar. Yeah, it was probably mentioned once, something like "They used to be at war, but now after the Calamity, it doesn't matter." Right? I remember clearly though why *beep* decided to *beep* after *beep*. ;) Which basically happens right before you get into the swamp with the gators.

In the best interests of making this thread alive again (IT IS ALIVE), I shall commence this with a wonderful, Halloween-themed game!

I haven't actually played this game yet, but you can choose from a two different protagonists and you're on a quest to save your town and during your journey you come across all kinds of monsters - but have no fear, for you can turn into one as well, the same goes for your companions!

So... how do you turn into monsters? Metamorphosis? Shapeshifting? Magic?

Considering the hints and the Halloween theme, Imma say it's Costume Quest.

Yep! :) It's your turn!
Hah, you were up quite late/early! I went to sleep right after posting this.

In case you're not familiar with the game, in Costume Quest you turn into the monsters by donning a costume and then magic happens which transforms you into them. :)