Best way to do gravity? (Performance)

So I have a simple game for iOS,

and it runs perfectly well on my pc but on CocoonJS Launcher it runs on 4 FPS (which is horrible),

and it must be because I have 56 blocks (with solid behaviour) and I need them to have gravity,

so the easiest way I found was to give them platformer behaviour and just disable controlls,

that way they don't move and have gravity, but that is ridiculous for a good performance.

What should I do for the blocks to have gravity and the game to run better/faster?

Custom movement negative vertical speed would be as bad as platformer behaviour?

It's not clear what your blocks are doing? Falling? Are they act as platforms? Are they all "on screen" at once? Sounds like something else. More details and a screen shot would help or better yet a .capx.