I quite like the concept, and the mechanics work well with the chameleon vibe. I think for me it seems like the guard instantly knows where you are at all times, so is always just following you. If you were to continue working on this game, perhaps it would be better to have the guard follow a set path, but then follow you if he sees you, or if you are within range, then it gives the player a little more manouverability around him. Alternatively, perhaps the player could also just be given a bit more time to get away if he walks past you and is not facing you, as it doesn't make sense that if he didn't see you that he would suddenly turn around. This would also just give the player a little bit more of an opportunity to get away. The camouflage timer also feels like it ends quite quickly for me, but it could just be because of how the guard moves.
I think the placement of some of the family members also felt a little awkward for me as well. In particular the family members at the ends of the level were difficult to get to, because I think it doesn't leave enough time to get them out and hide before the guard comes by again.
Overall, with a bit of balancing, and maybe reworking some of the systems around the guard, I think this could be a solid piece.