�ould you give an example of what you are trying to do, because it doesn't sound that hard to do if I'm understanding you..

Indeed Hoyer

<img src="https://dl.dropboxusercontent.com/u/48563442/fly%20movement.jpg" border="0" />

just fooling around a bit with the values wil probably make it even better.

And I used bounce of solids for the edges of the layout, there is probably a more elegant solution.

The biggest issue in this is making sure the picking is right, so you don't destroy the spawned sprites at the same time as the sprite shot.

Here's one way to prevent such an issue:

touch to destroy and duplicate - capx

In later posts in the topic I linked are some people asking what seems to be the same question and getting answers. But maybe I'm misunderstanding your question.

You could set it up as a global variable, save it with webstorage and compare it when restarting the app. That way you'll know how much real time has past.

improved

I added a global variable for speed.

There are some tips in This topic

system compare two values - if score > 100 - enemy set health to enemy.health+10?

There's a lot more you'll have to take a look at, but if you add touchobject is overlapping platform1 under system rotate is 1 only one platform is turning.

Instead of making rotate a global variable maybe it would be better to make it a variable of platform1, that would start making the events easier.

Something like this?

fly-example

System every random(0,5) seconds - spawn box?

Construct2 doesn't have an expression for it itself, but:

You could use this plugin