Are there 4 playable characters or just 2? Everything I've read stated there will be two playable characters... But on the character section of the website... It shows unrevealed shadows of 2 other characters... are these unannounced characters? http://www.huntedthegame.com/index.php/en/characters

That was the first thing that caught my eye as well. Perhaps those are Seriphine and Annuvin? Although I'm guessing not, I don't think they'd put up playable characters that are only available in specific pre-order packs - perhaps they're different bonus characters. That is, I'm pretty sure the basic game just involves Caddoc and E'lara but two of the pre-order packs include bonus characters you can play after completing the game (Seriphine and Annuvin) and it's possible these mystery characters fall in to the same category although they're available for everyone.

The character on the left is obviously Annuvin, the characters will most likely be unlocked by beating the game as one or both of the first two characters. Annuvin is not unlocked via a pre-order pack, just the items in the pack pertain to him.

Although this may not be correct it is the assumption I'm making with the information at hand currently.