From what I played of it, the only times I screwed up and got caught (which is an instant fail, since leaving each floor requires every character you have) I knew exactly what I did wrong. There's also a Heat bar, which if my assumption with the interface is correct, there's a total of 18 points you can accumulate before you fail (I assume, I think my highest was 5) when a guard just seeing you adds 1 point and getting seen by a camera adds 3 points. On the fourth or fifth stage you unlock access to the Video Magnet tool, which lets you erase video once per camera station, removing 3 points from the Heat bar.
This is why the 1,000-word limit on the review was a bit annoying...couldn't fit everything in the review, so I figured I'd need to hop here and explain stuff I couldn't fit in. :/
