Iirc, someone mentioned that it's not possible to continue the game from where it has been left off, as other than the main sprites, there isn't any data that can be extracted from the game due to Oseos meddling. Pretty sure I remember him saying something along the lines of not wanting to make it open to mods/third party coding until after he finishes the game. But that isn't exactly gonna happen anytime soon...
Someone could realistically remake it using the sprites available, or with creating new art (Not a very complicated art style), but it's just the matter of having to rewrite and re-code the entirety of the storyline and events, as well as recreating the map too. Hopefully someone of great talent does pick it up soon though, this game has too much potential to go to waste like this thanks to Dr Stones.