Thank you so much for your reply (and for checking out the project's page and appreciating the presentation too) !
For the guitar sounds I used exclusively NeuralDSP amp simulators, quite flexible and can produce very convincing sounds so I can recommend for all things guitar related (they have free trials too).
Concerning the stories, I guess most people who didn't go through the whimsical interpretation of the picture saw similar motifs in it (family figure, reflections in the bubbles, brevety of a bubble's lifespan...), so it is only natural that the end result would end up quite similar in that regard.
To go with the theme of my story, I can also say that there is a reason why there are specifically 5 tracks that are named this way and why the chapters' stories are describing these different situations.