So, state of the game:
The GUI is what I call a "Button-GUI". I have programmed the buttons from the ground up, and therefore have full control over them.
The currency in use is S.I.M.P.U: Simulated Ingame Monetary Payment Units. Simple and to the point, huh? xD
At the time of the initial upload (I hesitate to call it a "Release") the most basic functionality is in. You can build a tower and ... well, that's it, really. :-)
Oh, here's the juicy part. I'll go through it by themes:
First, you won't be unlocking condos by building offices and so forth. You'll have full access to everything from the start.
Big Condos will cost an ungodly amount of S.I.M.P.U., however.
Appeal: At the moment, any office or condo built will immediately be rented/sold. That will not persist. The tower's appeal will dictate how full your tower will be: A beautiful, safe, self-sufficient tower will be full to the brim, the other tower will be quite empty.
Infrastructure: I have never liked micromanagement too much. So, you won't be building phonelines, waterlines, powerlines. You will build the corresponding connections to your tower in the underground parts of your tower though. As they will be able to fail it's always good to have redundancy - but they'll also be somewhat expensive of course.
Waste disposal will also be something to keep in your mind of course.
Emergencys: There will be fires, thiefs, accidents and sicknesses. There will be 2 ways to deal with those: Call in outside help, which will take a bit of time as the fire fighters for example have to mount their trucks and drive to you first. The second way is to have the corresponding emergency services office in your tower. Those will be quite costly, but in a 30-story tower you want to put out the fire when it's still an infant.
A local security office will be able to, with a bit of luck, stop the thief before they get the contents of one of your vaults. Outside police can only be called after the theft, and getting back stolen cash is not very likely. A bit, maybe, but not all.
Vertical Farm: As a great fan of Sim Tower and Sim Farm I decided to make both - but as I cannot wait to make the farm game, I am including a form of "light" version of that in here. There is already a farmer's office and a grower in the game, and there is a way for you to build them - but they have no functionality yet. When they do, the farmer will grow a great variety of crops and store them in silos in your tower - the local shops will then take that produce and sell them.
The benefit for you is that a tower that has any kind of self-sufficiency automatically has a higher appeal.
Hotel: Offices and Rentals give you money every week, Condos once. That may not sound too appealing, so one way to get faster income is building a hotel. There will be management, several different sized suites, and a cleaning office. There may also be personnel elevators or personnel stairs, I have not yet made up my mind on that. This is not a carbon copy of Sim Tower, after all. :-)
Fireworks: I grew up with a big fireworks every year. So, I quite like that and will not make the people in your towers go through life without them. There will be several different kinds and their respective producing offices - but keep them away from heavily populated areas - one spark would cause you a pretty large headache otherwise.
And shooting bit rockets into the sky right in front of your tower might also not be such a good idea...
There will be Schools, Universities, Chapels, Industry, Movie Theater, Theater etc. in the future.
Also, I am thinking of using the ground: Oil to drill for and process and sell, Minerals to mine and process and sell, a Magma layer on the bottom that might become lively if the right conditions are met.
Lootboxes: One word: Nope. Nada. Never. Nyet. Uh-Uh. And that's a lifetime pledge. I will never make lootboxes, ever, in any of my games. EVER.
That's what the cheat menu is for, after all - and of course the corresponding "Achievement". ;-D
DLC: Most likely free for all eternity. Definitely free for the foreseeable future. Not that that were of any real concern just yet. ;-)