Here it is:

welcome, I'm glad that this helped

do you really have to move the background? I would advice to make the layout bigger than the screen and use the scroll-to behaviour.

I tweaked your example a bit and like the result. Hope this helps.

can you upload your .capx? As said, mine is just a simple mock up with one of many possiblities on how to make this effect happen.

If you upload your .capx (if you don't want to share everything, just strip it down to the important stuff) and I can have a look and give proper advice.

A quick mock up of one possible solution (I can imagine, that there are even better ones, but hope this gives you an idea)

You can have the following:

1. up to 50MB APK File

2. up to 2 extension files with a limit of 2GB each

So, what you need is provide stuff like music as an extension file and have your game load the music from there.

No idea, how it can be done, as I have not played around with Google Publishing yet, but I am quite sure that it is somehow possible.

not quite sure what the problem is, but does this fix it?

A sprite is always present until you destroy it, no matter if it is visible or not.

even whey they are invisible, the location of each single particle has to be calculated.

not really... for the recent releases, I were always close to the lightning draw.

I'm usually at work, when a new release is available, my browser just triggers me that I got a new message on twitter, I click that little bird in my browser see that it is scirra, click the link, hit the download button and done.

Could also be that he is an active twitter follower... I managed the lightning draw with the last release, as I have a plugin in my browser which instantly notices me of a new tweet... saw it, clicked the link and downloaded.