Yes, it doesn't work after pressing R :/ Web version has the same issue.
For the particles - they indeed jiggle, but it seems to happen almost always if there is more than 5-6 of them on the field.
Ah, yes, I see the bug now. I’ll fix it at least in the web version.
The collision engine is probably acting funny. I won’t get into that now but I’ll improve it for any eventual future versions.
