Thanks a lot for playing Sleepless!
There were definitely a few easter eggs/sidequests in there that a player could have reasonably missed, with the amount of classrooms and all. You could go the entire game without finding the secret shop on the first floor, which really isn't a huge problem since you can finish the game with just the equipment you have. At first I considered putting in an (optional) quest marker for NPCs that would give out side quests, but I figured that it would just encourage players to talk to the quest-givers and ignore all the other NPCs. A future update would probably have a rumormonger student that would hint toward the side-quests that are available on a certain floor and a way to track quests that are in-progress.
I'm glad you enjoyed the various classrooms and all the different students who populated them! I did put a fair amount of effort into NOT just copy and pasting everything, though I can't really say the same for the hallways. I was considering putting lockers into the hallways to decorate them a little, but I thought it clashed with the look and feeling of the school.