Or what would you change about RCT3 (since RCT4 mobile wasn't that greatly received)
For me, I would like them to add a ticket booth where the peeps could actually purchase their tickets.
Create your own library of objects for the ones you use the most.
These are a few of my thoughts..what are yours?

The first thing that comes to mind is the ability to be able to customize the menus but I think that’s related to what you’ve written. I’d also like the interface to be like windows. The RCT3 interface is a bit awkward to use.

And instead of getting a message that the game is sorry and needs to close, perhaps a message that tells us exactly what the problem was.

And instead of getting a message that the game is sorry and needs to close, perhaps a message that tells us exactly what the problem was.

And autosave so we don't have to redo everything.

And that too!

And the ability to copy and paste stuff from one area of the park to the other, including stalls, facilities, enclosures, terraforming and staff with their patrol areas.