Particles acting differently on play

Hi,

I made a very simple rain particle system with a sub particle system for the splashes. It works fine when not in play mode, but on play it seems like the collisions don't register and i'm stuck for solutions.

Here's the link if anyone wouldn't mind checking out the scene: https://www.sendspace.com/file/f6flar (its 45mb, unity 5 project)

Thanks

Scene View:

Game View: