Yet even if your team is quieter than a shadow wearing plimsolls, your presence won't go entirely unnoticed. With every turn, the building's "Alarm counter" increases slightly, and at each new alarm level the game becomes slightly more difficult. New enemies are introduced, more cameras are switched on. The game gradually piles on the pressure, increasing your obstacles and reducing your resources.
This is a brilliant way of imbuing the tension of a heist movie into a turn-based game. Combined with the procedurally generated building layouts, Invisible, Inc transforms into an emergent delight. There'll be times when you're madly searching for the exit teleporter with a swarm of guards nipping at your heels. In other missions you'll find the teleporter within the first couple of turns, and then it becomes about how deep into the complex you're willing to go, how much you need to rescue that extra operative or raid those safes you pass on the way out. Invisible, Inc strikes that risk/reward balance perfectly. Playing it safe might work in the short term, but come that final mission, you might yourself lacking the necessary equipment to survive.
That's how Invisible, Inc stacks the bricks. Here's how you knock the tower down. You assume control of up to four agents, all of whom are highly customisable in terms of their abilities and equipment. They all control in the same basic way, moving silently unless you tell them to sprint, and slipping automatically into cover when you position them next to an object or a wall. How you equip out your agents will affect your approach to the missions. You might rely on speed to slip past enemy patrols, or soup up your hacking AI Incognita, providing her with enough "PWR" points to crack any firewall with the force of a wrecking ball. Or you could opt for a brute-force approach, dispatching any guard you come across with stun-guns, dart-guns or regular guns.
But for every move you can make, the game has a potential counter-move. If you knock out a guard, you need to pin them to the ground to prevent them from waking up, at which point they will stop patrolling and start seeking you out more deliberately. If you emphasise hacking, you put yourself at risk of "DAEMON" viruses, which have a range of negative effects from increasing firewall protection on certain objects, to knocking out Incognita completely for several turns. If you try to sneak past guards, there's a chance you'll be spotted, at which point you have the opportunity enlist the aid of another agent, or move one square into cover before being mercilessly gunned down.
Choices abound even when it comes to teamwork. Keeping your team closely knit is always the safest approach, but it's also the slowest as the maps usually sprawl in different directions. Separating enables your agents to cover the ground quicker, but if one is taken out, it suddenly becomes a lot harder to extract them to safety. This is what makes Invisible, Inc so engrossing. Every turn there's a new decision to make, a new element you have to deal with, a new scene in your little spy caper.
There's remarkably little in the way of obvious flaws, either. The presentation is exceptional, not just Klei's wonderful artistry, but the soundtrack and voice-acting too. The game is also very clean, with no bugs or balancing issues. Indeed, you can make the game as easy or difficult as you like through a wide variety of game modes. The only complaint I can think of is the story is fairly slight, and the characters only lightly sketched.
But even this seems absurd to identify this as a negative, because it's so obviously a framework for creating your own story. Invisible, Inc is a game of perfectly executed heists, of disastrous rescue missions, of heart-stopping escapes and heartbreaking last stands. It knows precisely what it wants to achieve, and has the focus and intensity of a Bond-villain's laser. For £15, I expect you to buy.