I don't use audio so I have no idea what it sounds like -- but game mechanics wise this is very well done. So far I haven't hit a wall but there is a coin currency that you can get IAP for. The one mission that asked me to use coins gave me a reward for even MORE coins so so far so good. There is much variety in the missions and many visitor tasks as well. Some are a seek and find type, others are bring me to a level type. Just nicely mixed. I dunno how long I can keep it up for and if I would be as dedicated as I was to Tiny Tower (which my only negative so far was in the app description saying 'who needs a tiny tower') but for now it gives me something to occupy me with.
Oh, can you move a floor once placed? Can't find that option. Especially since there are bonuses for placement next to another floor.