I don't know much about Gotot, but it's good that you are making progress in learning the engine of your choice.
Saving and loading especially for web games can be difficult.... For security reasons, certain things can't be done in HTML 5 games, which is a bit frustrating for us as developers, but obviously necessary.
From the software industry I always hear the "Aim for 80%" and that's perfect.
I think the problem with software, games and game design is that there is no 100%. There's always something... there's always a tiny bug.... there's always this behaviour that doesn't work 100% the way it was intended, there's always this animation that's not 100% perfect and so on. There's always a workaround for some problem....
So once you polish to 80%, you're basically done, because everything beyond that is always and a never ending process of improvement :p
Leave them Wanting more is important for the Jam you are right, but also applies to published games, especially if you plan to expand the game after release. So you can bring a second game, an update, an expansion or something along those lines.
I think you did a good Job with your Game