The other is 'assassinate these people without being noticed', which is really frustrating because of the 'without being noticed' clause. While you're on the mission, people who normally wouldn't care about you will attack you for no reason, not only forcing you to run all over at random until you break line of sight and find a hiding place, but resetting the mission. Which gets harder the second time around, since the bodies of the first set of people you killed will be lying there making their resurrected clones extra suspicious.
The least satisfying part, though, is the 'assassination memories' themselves -- they make it sound like you can stealth-kill the person and then escape cleverly, according to the clues you gather, but the enemies always see you coming a mile away and challenge you to a swordfight with dozens of guards, and then after you finally kill them, the clever escape route either doesn't work or isn't obvious enough for me to ever find it, so it's 'run around at random until you break line of sight and find a hiding place' again.
But it's creepy, at least. Especially the 'present time' sections which look even more like a computer simulation than the computer simulation. I do want to assassinate the fucking informers, though.