Lucky you! 
You know, I want to be cuddled, I don’t want to e.g. look out for all the stuff like loading different resolutions for different screen/DPI sizes, I just want to use display.newImageRect to care for dynamic scaling.
I really don’t have the time to code everything myself or test lots of different assets from the asset store etc. - I want to concentrate on game design, playability, art, style, etc., not reinvent the wheel again and again (even if this would give me some more freedom).
What did we need for “Freeze!”?
* Corona PRO subscription
* gtween lib (free)
* particle candy lib (paid)
* LevelHelper (as a level editor) and SpriteHelper (for sprite sheets), both paid (and worth every cent)
And that’s it, the rest was game design, coding, art, level design, lots of testing. And some luck, of course.
I’ve seen lots of Unity projects that were less complex, but needed way more 3rd party plugins and coding than our game.
And yes, there are quite powerful libs and toolsets like “Unity 2DToolkit” (I use it) out there that make dynamic scaling quite easy. But never as easy as in Coronalabs SDK.
And after doing games for many years (I released my first games internationally in the 80s, most of them on Commodore C64 and Amiga) I really like easy.
But it’s like loving & hating music - lots of different opinions. Just wanted to share what I think about “Having a problem with Corona? Oh, just let’s switched to Unity, and everything will be fine”. Might be the correct solution for some people. But if you’ve never coded in Unity first download the free Unity version and invest a few weeks of your time and try it out, before you say goodbye to the rest of us. We would miss you. 
Best,
Andreas