A variety of factors! I was falling out of the fandom at the time, had a bunch of troubles with RPG Maker, and very quickly got bored of the visual style RPG Maker required me to use if I didn’t want to do every single background asset from scratch. I even struggled with getting the visual look of the cutscene graphics to look like I wanted, so they feel inconsistent and like some would need redrawing.
Plus, it’s a quite complex idea for a game. It’d take a super long time to develop, requiring a lot of graphics, writing, level layout design (a weak point of mine), script coding, and even custom from-scratch code to make the foal collection work.
It’s just all too much time and work required for a game that can only be advertised/sold to a niche fandom with a cruel and hated reputation.