Just when you thought you've done everything you could do in a Far Cry game, this fourth installment gives you option of embarking on a 'spiritual journey'. Narratively exclusive from the main plot arc, said journey sees you become Kalinag - a warrior based loosely on legends inherent to the Himalayan region in which Far Cry 4 is set.

There are a number of missions to undertake as Kalinag, all of which take place in Shangri-La; a mythical enviroment separate from the main game and accessible only through supernatural portals. Usual rules and physics have little meaning here, with warp holes transporting you between floating islands, enemies harbouring superhuman strength and white tigers that can become invisible at will.

Entering Shangri-La is completely optional, but it has been designed with a view to better impart a small slice of the mythology that surrounds this area of the world and has informed Far Cry 4's broader design choices. Even the most unassuming of elements have been given a surrealistic twist, with grass glowing red, rivers running with blood and prayer bells spinning in violent perpetual motion on the ground in defiance of gravity and friction.

The enemies in Shangri-La are more powerful than usual, both in terms of their ability to deal and absorb damage. As a means of leveling the playing field you've got two mystically powerful tricks of your own in the form of a time-altering bow and one of the aforementioned invisi-tigers.

Drawing back on your bow triggers time to stop until your grip releases and the arrow lets fly. This gives you ample opportunity to nullify your opponent's extended health bar by aiming solely for headshots. It's a trick that comes in particularly helpful when confronting the bigger, bulkier 'Scorcher' enemies - magic users that can breathe fire.

If you do find yourself in trouble your tiger will defend you of its own accord, attacking anyone acting aggressively towards you. Better than that is the fact that you can use the tiger to silently assassinate enemies. It's this command that triggers it to become invisible, only reappearing once the target is vanquished.

Other elements remain uniform between Shangri-La and the rest of the game. The same visual cues highlight which ledges can be scaled, healing yourself means stopping for a short while and holding a button until you're back to fighting fitness and all basic commands (jump, shoot, crouch etc) are unchanged.

Ubisoft is refraining from revealing how many of these quests will be available, other than saying that there will be 'several' and that completing them all will tell a complete story in its own right.

What's most striking about Shangri-La is how a few changes to your weapons and the wider aesthetic present what feels like a completely separate experience. It's a direction that highlights just how impactful even the smallest subversion of expectation can be and is something other design teams would do well to learn from.