0.3 just has the most content, a trial version that contains most if not all of the first area up to the area boss. The creator releases smaller updates containing individual animations coming from their work on later parts in the game but as more or less completely separated zones containing individual enemies that they implement, without animations from previous versions, and not a complete trial like 0.3 is. Hence 0.3 is the one here, also 0.32 is just 0.3 but with bugfixes and one extra scene iirc.
But they update regularly on Ci en and patreon, about 1 to 2 times a month