We start off Week 1 with a level which is already a bit of a challenge, but not so difficult that you would get stuck on it.
When I make a particle system from my drawing. the material used is a "runtime material". this creates lost referencing when serializing it into a prefab.
Steps to reproduce:
I notice a bug, where the eraser doesn't properly "erases". Whatever was there before remains when displaying in certain shaders.
For example some default particle shaders still show it.
I'm using unity 2018.1.0f1. and this example shows the bug is shown with the particles/alphablended premultiplied shader.