haha this is such a fun and novel concept! Nothing suspicious about seeing someone running past a curtain where a wall should be. And a very funny ending too :) One thing that would would make sense to add would be to have a little alarm before the fella comes in to check on you to give a bit of a heads up. At the beginning before I got the rhythm of it, I was a bit surprised when all of a sudden I lost.
Anyways, very fun and a really well executed little game, well done!