No, yes, maybe…
Depends on how the game is written. If it is written in a compiled language like C, or with most "game maker" programs, it will be converted into machine code that ONLY runs a Windows PC. You would have to recreate the program to run on Android, MAC, Linux, etc.
If you create the game using JAVA, the code is NOT complied into machine code, but is run withinthe "JAVA Runtime" program that the users would have to have on their PC or device. The Runtime allows the same code to work on a Windows PC, an Android Phone, MACs etc. That is why so many apps are written in JAVA, and many web apps are in JAVA. It will run on anything,
However JAVA is always slower and less secure that a compiled program, The compiling has to happen while the JAVA program is running.
Also it does NOT solve the issue that often you have write multiple code with a program to change the way things display because of the different in size and dimensions between a PC screen and a phone screen. So even with JAVA you often end up having to write the code "twice".
It'll need some changes.
You can also design it to run on Android and as a Chrome app, that might be an easier way to get it running on both computers.
But the basic idea is when you compile a program that is converting it into machine language that the computer can run. It's very possible to write a program that can be compiled into different languages (like Windows or Android). Lots of games will have a version that runs on different OS's.
No, unless you wrote it in a cross-platform development system that can build for different OSs…
With a decent one you can write in eg. C/C++ and just select which platform you want each time you compile it.
At the other extreme, if you use a maker-specific language (eg. any .net, Swift) or java, you are locked out of various platforms unless you re-write from scratch.
noep. they use different systems. just like you cannot play Apple games on Androids…
Yes. Use HTML5 and you can port it to the Apple store as well.
Yes, but you WILL need to re-platform it. There are tools to make the porting MUCH easier.
Yes, U can…