Mood: The mood of the video appears to be melancholic and introspective, with a theme of heartbreak and possibly longing. The use of pastel colors and the title 'Heartbreak Mashup' suggest a somber and reflective tone, while the presence of multiple individuals may imply a sense of shared emotions or a collection of heartbreak stories.

Environment: The environment or setting of the video is not explicitly clear, but based on the aesthetic, it could be a modern, urban setting or a stylized, abstract space. The confetti-like elements in the background may suggest a sense of celebration or revelry, but the overall tone seems to be more subdued, indicating that the video may explore themes of heartbreak in a more introspective or artistic way.