I have a native iOS game (objective c, XCode build) which I am considering to port to other platforms.

Core gameplay is based on solely on geographical maps, and custom drawing over maps. It also has Core Data. This part is complete in development.

What is not done yet is: monetization, gamification (leaderboards, challenges) and multiplayer functionality.

As I think more about it, I am tempted to think if this is the right time to move to a cross platform tool such as Unity. But before dedicating time to port my 5 years side-project effort in Objective C, I really want to know if its worth it.

- Does Unity support such plugins / assets that will fulfill all my above requirements?

- Unity Personal seems to have only 20 concurrent users - is it too costly scaling if I decide for extending to web and android platforms?

- What is the general workflow involved in publishing to iOS, Android, PC, and web platforms while using Unity? I mean to ask about various points of signing stuff, paying fees and getting certified.

- How long will it really take to port my entire Objective C project into Unity? I am somewhat familiar with C# but I am finding it hard fidgeting with Unity IDE as lot of things are focused around FPS and 3D while my game is still 2d - not much action involved. I seem bit overwhelmed by the list of features I see there. All in all, I do not want to lose my momentum while still making sure its portable to everywhere.

- Any assets I could use (for free to try basis in debug) that are relevant for my game?

- Last but not the least, are there any costs that I need to be paying upfront to Unity, for using it (apart from their monthly subscription model)? I don't understand their costing for multiplayer in conjunction with their subscription fees - if someone could kindly elaborate.

Thanks in advance for your time reading a newbie