For no particular reason (I just threw a hypothetical dart at the list), this month’s challenge is to create a picture with every single layer of synfig used.
That’s all the gradients, all the distortions, all the geometries, filters, others, etc… You can have multiple of each, but at least one of each.
I don’t recommend doing them across the whole canvas - you’ll end up with a horrible mess The ‘onto’ blend mode may be your friend.