Gameplay (yes, I'll still call it "gameplay", despite the proceeding paragraph) is simple. You build a tower from either residential or business floors. "Bitizens" live on the residential floors and are assigned jobs in the businesses. Each has a set of stats matching their skills against each of the categories of business. Matching a bitizen with a job they're good at makes them happy — which I presume increases their efficiency somehow, maybe with faster restock times or better sales, I haven't been able to tell which.
There are two currencies employed in the game. One is coins. You use this to buy stock for the businesses and to purchase new floors for your tower. It's generated by the businesses selling their stock. The other currency is towerbux, and it has a far more insidious role.
It's perfectly possible to play Tiny Tower without ever using towerbux — but it would make for a slow, tedious process. In short, what towerbux do is they make the game fun. You pay towerbux to shorten the drawn-out processes of building floors, of restocking businesses, and of selling that stock. Sure, there are occasional bonus lift users who will perform these tasks, but their random appearances cannot be relied upon. (And, yes, you can leave the game and come back later to see how things are going — the app giving the appearance of running in the background — but that isn't the point.)
You get towerbux in one of two ways. The first is as a — often random — reward for performing some task, such as locating a bitizen or taking someone up in the lift, or as a bonus when purchasing a new floor. The second is by buying it through in-app purchase. Yep, we're in the land of freenium here.
So while you're playing the game — while you have the app open in your hand — what will you be doing? A small amount of your time will be spent on hitting the buttons to order more stock for your shop, but most of it will be taken up by pointless make-work tasks, predominately moving bitizens about in the lift. You earn a small amount of coins for this, but ultimately all it is doing is providing you with something to keep you busy while you're waiting either for some long task (restocking, building) to complete, or while you're waiting to earn enough money to buy your next floor.
So why have I been playing it so much? Why have I checked it a dozen times during the writing of this piece? Why will I continue playing it for the rest of today, and probably get caught checking it during work tomorrow? I wish I could put my finger on exactly what it was. There is a satisfying sense of achievement as you hear the money clinking in and watch your tower grow. There's something which makes you want to see what you can build next. There is something, ultimately, rewarding in the experience.
