How to write a cross-platform game?

Question

HTML

Good afternoon. Such situation. Programming is a hobby for me, I just like it. I really wanted to write a cross-platform 2D game a la Mario (well, maybe better graphics). But I can’t decide what to write on, so far the options are:

1. Write a game in, as is now fashionable, html5 (hybrid application). First, just in the browser, then port it (to android via PhoneGap, for example).
   
2. Use cocos2d-x (c++)
   

I'm leaning towards the first option. It seems to be much easier. But will html5 work? Games that are freely available on this technology are already very primitive (Yes, and the source code, it turns out, is always open. And if you write in cocos2d-x, will there be many problems with porting to Android/iOS?
PS It is desirable that the toy will run on Windows, Linux, Android and iOS Thank
you.

Answer 1

Unity3D.
True cross-platform, including browser and mobile devices.
Tailored for games.

Answer 2

And the source code, it turns out, is always open.

Do you think someone is interested in the code of the next clone of Mario? Tutorials on how to create a platformer on some HTML5 engine - a wagon and a small cart.