Wow, I was quite interested in seeing just how well I could be hidden. It was really interesting to see everything constantly move. I know that might not sound very engaging, but it was for me. That music is so fitting for a security game. While the graphics weren't much, they didn't really need to be. What I liked was how complex it got.
You really had to specifically study all of the actions and know what was going to come up next. Everything is done in an organized manner. I like the prescence of passcodes. It's not just straight through, you have to unlock certain parts. It might not make sense, but it's good.