In a stream on Twitch, designers James Lantz and Jason Dreger walked through a stage. The isometric levels are procedurally generated, so the pair were feeling their way through the stage the same way a player would. We only saw a team of three today, but they noted that in the current build you can have up to six team members, among an undecided number of classes. You don't need all of your team alive to finish a level, but the ones lost are dead forever.
Klei noted that the game is about balancing caution and speed, since a constant alarm will be ticking up as you make your moves. Once it hits level 20, an elite squad of Enforcers will come looking for you, so you'll need to move as quickly as you can while still being careful. The final game will include ways to lower the alarm. They'll also be tailoring tougher boss-type encounters that aren't procedurally generated.
"We're expecting you to lose a lot, to restart a lot," said Lantz.
As the Operator commanding your spies, you can swap to a "mainframe" mode to see more information. This also lets you spike CPU servers and safes with points gained from hacking computers. That will give you access to safes (for upgrades) and cameras for a fuller view of the floor.
Incognita is scheduled to release on PC in 2014, and Klei says it in the process of deciding on other platforms.