Basically, this is my hobby project. It takes too long for each update because frequently I get distracted by something, or work takes 10-12 hours of my day (I have worked for almost a year in a nearby city, so when counting for transportation and lunchtime, I passed 12 hours of my day working), right now, my work is in the same city, but it's a little far and I still don't have a motorcycle nor car, and there are no buses close, so I have to walk most of the way, which is good for me to make some exercise since I'm too sedentary and like the PC as my entertainment, but it also consumes 1:30 hours of the day, plus lunchtime, which I stay in the work, because it's far from home, that makes it 10-11 hours of my day.
I also like to play video games and watch anime, so sometimes I get distracted with something and do not get in the mood to work on the game (like recently with Factorio. Curse that game, it's good, but too addicting). It also doesn't help that some parts of the development aren't that funny to me, like mapping.
I do intend to finish this, and I took about 4 years to finish the first part, so I'm the first to recognize how much I procrastinate.
As for the content of each update, it's an entire section of the game. For example, the first release went until the first battle with Alma Elma, covering the entire Ilias Island, the second release covered the entire Natalia region until Sylph, and now the third goes until Gnome. Of course, after each release, I fix the bugs and add things that were left out from the release. But since I take so long to post anything, I prefer that when I post it, it must have a good chunk of content, about 8 hours of gameplay to justify you replaying everything if you don't remember what I did prior. As consequence, yes, it takes a year or more in between updates.
Thanks for playing the game, sorry for all the delay.