Hi! Nice to hear you like the game. ^_^
As for the game engine, I am just one person, and I thought going for something easy to use was better, if I wanted to keep a decent flow of updates (plus, I felt RPG Maker worked fine for the kind of game I had in mind).
My next game will use Ren'py, for similar reasons (that's going to be a sequel to one of my older games). I am not against learning other engines like Unity, but there are a lot of things to consider when starting a project, so I don't want to make promises on whether or not I'd use Unity in the future.
Thank you for playing the game, and letting me know you enjoyed it. :)