They are still working on it through patreon it looks like. Level 5 on its way. Here is what they said:
I think we will have a playable version of level 5 out in february! There was also a delay on the music from our music artist, but it should be done this month. I expect we will have 3 or 4 enemies working. The full level with the boss fight will take a bit longer, my guess is after summer to have the entire level complete with the Fae bossfight.