Nice, reminds of old flash-based stealth games. The idea is pretty cool. I couldn't figure out what to do at first but I eventually got it. The circular indicators seem more like scanning progress then counters for getting caught. Also, it's weird that you have to use mouse to answer questions.
I didn't win because when about 2/3 of the class finished I there was no one who could give answers for the first question. Since it's random, it felt a bit unfair. But I enjoyed playing it!