I machine-translated a long text, so the sentences might be strange. I apologize.
I wish Desert Kingdom would be released on Nintendo Switch. However, it seems that the staff said "it wasn't a title that could be released on PSP," and it's considered a difficult title to make a profit on. However, I couldn't find a source for this statement. It might just be fan speculation.
Also, Seishun Hajimemashita!
The parent company of this game went bankrupt.
It seems that popular titles were transferred to arithmetic,
(https://www.arith-metic.jp/contents) but Seishun Hajimemashita! is not among them. Where did the rights go?
But there's still hope. Akaya Akashiya Ayakashino(Of the Red, the Light, and the Ayakashi) was in almost the same situation, but it was released on the Switch by Dramatic Create. Apparently, this was made possible because there was a passionate fan among the Dramatic Create staff. So, Seishun Hajimemashita!... too... haha