The way the game is structured it's easy to leave a tough level and come back to it later – possibly having learnt new ways to get round something. But despite using very simple stock mechanics, rapidly across the beautifully-designed and beautiful-looking levels, the puzzles get fiendish. They build from really simple ideas (use a gizmo to make a door open, direct a beam of light to a switch etc.), so simple they never need an explanation or instructions. Thankfully, however you play, the puzzles are superb. And it's entirely possible to play the game without engaging with the philosophical stuff – although you'd be missing out to do so. Rather, the two sit awkwardly alongside each other barely acknowledging the other's existence. This is not entirely successfully woven into the narrative. Underneath that narrative, there's the actual business of solving puzzles and unlocking new bits of gorgeous ruins, in order to solve new puzzles. Reading between these lines, in the conflicting and partial voices, you'll start to discern a narrative – but one that asks far more powerful questions than it answers: what are "you"? Who is God? Is consciousness something that is tied to humanity, a "soul", insubstantial, or is it a network, or an emergent behaviour, or something else entirely? Can consciousness be transferred? And, just perhaps, what the hell is the point of "us" anyway? Instead, as you solve puzzles, you'll find strange terminals dotted about the place, filled with stories of Greek myth, emails from scientists in a world at the edge of Armageddon, and, just perhaps, a chance to talk to someone else – someone who is telling you a decidedly different story to the voice in the clouds. Quite why you're solving puzzles is initially unclear, as is why you're told not to go anywhere near the gigantic tower up into the heavens on pain of death, or even what you are. Awakening amidst what appears to be the gathered together ruins of the most beautiful bits of human civilisation and history, you're a robot(?) that is told to solve puzzles by a booming voice in the sky that calls itself Elohim.