Completely finished the game in 2-3 hours (which is pretty long compared to other visual novel games I seen). It was a really heartwarming game and I absolutely loved it; I hope there will be more soon!
The only (small) problem here is that there is no autosave feature, which means you need to regularly save your progress in case your computer or the game crashes.
Edit: There seem to be an autosave feature provided by Ren'Py every one or two minute