Well, the High Rise Invasion manga ends with a resolution that ties up most of the loose ends. The heroes succeed in their battle against the odds and there's a sense of closure for the story. However, some fans might have wished for a bit more elaboration on certain aspects.
The ending of High Rise Invasion manga is quite complex and leaves some room for interpretation. But basically, the main characters manage to overcome the final challenges and find a way out of the dangerous high-rise world.