Depends on how you define it.
Lemma’s story is done as far as I know. But there are stories which were only on the Patreon, which will be released to the rest of the world in about a month when the Lemma book comes out.
There are also other stories set in the same world at various times.
But I don’t have any plans to write any other stories with Lemma in them. I might if the inspiration strikes, but right now I’m moving on to other stories.