I've made the game using RPG Maker MV and some free plugins and assets developed by the community (you can find the list in the credits). Some background elements are isometric screen captures of 3D assets.
RPG Maker is a really good editor and easy to use, and there's a lot of documentation and tutorial on the internet.
The hardest part has been to find a correct workflow for the developing process. It took three months from start to finish.
The English localization (I'm Italian) of all text needed a lot of work (and probably contains some mistakes here and there)
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