I don't quite understand the ending of " Midsummer Light Year "!

Light Years in Midsummer was a story about a group of young people looking for a new home after the end of the world. At the end of the novel, the protagonists came to a mysterious planet and found that there was a mysterious life form on the planet. They could establish contact with humans and help them adapt to the new environment. However, when the protagonists tried to leave the planet, they found that the planet was under attack by a mysterious force. They had to work together to escape the restrictions of the planet. The ending of the novel did not clearly explain the final fate of the protagonists, which caused some readers 'attention and controversy. But overall, the ending of the novel left a deep impression on people and made them look forward to the future development.