I was thinking to myself and finally realized why Solvalley does not give a sense of accomplishment: I changed the initial proposal of the game.
The original proposal: the player has a time limit (less than two months inside the game). In this limit he has to know the girl, develop what is necessary to attract her, to find her on the map, to make the right choices (for example, in the choice between Lucy and Milena), etc. At the end of the 50 days, he would have the reward: see the ending sequence.
If the player wanted another girl, he would have to start the game again and try to make another way, other choices, etc.
But as it would be boring to play the game many times, I decided to simply take out the time limit. Choices no longer make differences (so players can see all the scenes on the first move), a heart indicates the position of events, etc. So basically I took away any sense of accomplishment that the game could give, in exchange for an easier and more enjoyable gameplay for anyone who wants to follow the story.
When I finish all the events, I will dedicate myself to the 50 day mode and try to return this sense of accomplishment that no longer exists in the game.