How do I Decide What Layer For CertainObjects And Animations

In regards to the layers I have 5:

4 Player

3 Collectibles - appear after a crate is broken

2 Platform Blocks - do nothing except i have 1 block that can be broken

1 Traps - swinging spike balls, spears and spike platforms that move 90 degrees

0 BG

I thought i read a post talking about what to have and not have on each layer. Right now I have the blood animation on Layer 4 and the breakable(s) animation on Layer 3.

Will this be okay, or should i move the animations to a different Layer?

Thanks for any help and tips.

Of course you need to consider what you want to be visible if objects overlap as the object on the higher layer will any on lower layers. But I think I read something about keeping images that are rendered similarly on the same layer for optimisation purposes - I'll check my notes later, or you could search for optimisation.

It was on the Performance Tips page: https://www.scirra.com/manual/134/performance-tips

"Place objects using the same blend modes or effects on the same layer"

Thanks so much hundredfold. I must have blew right past that.