The dev had been in hospital and he said there could've been a chance there was no 2nd part at all due to the potential of them severely suffering from their condition.
There will be a 2nd part out either late 2025 or early 2026, but because of their condition it's obviously going to take time. I took the 1st Artemis game as a cliffhanger and accepted that would be it, but hoped for a 2nd and turns out there will be.