>>721077186
>>721077927
Any dramatic story about a teenager is going to be about growing up to some extent. Deltarune is a Bildungsroman for not just Kris but also Susie, and maybe Noelle and Ralsei as well.
We don't know however whether "the importance of moving on" will be a central theme or not, just as we don't know what happened to Dess. What we do know, however, is that a major motive for Kris is his promise to someone. This promise might be to do all this to save Dess, or for something else. The theme of the story could well be "Don't take oaths hastily" which is also the entire point of Tolkien's Silmarillion. For a modern work this would be subversive since the idea of oaths and promises being binding through life and death has largely fallen by the wayside.
>>721079935
He is helping to keep information from the player but I don't think he is malicious. I think he wants to keep the player working along whatever plan surrounding the Prophecy he is working towards.