Mood: The mood of this video appears to be lively and energetic, with a theme of showcasing a collection of popular music or dance tracks from 2015. The overall emotion conveyed is one of excitement and entertainment, suggesting that the video is a fun and engaging mashup of various songs or performances.

Environment: The setting of the video seems to be a virtual or digital environment, given the presence of the text 'HD VIDEO' and the title 'ZERO HOUR MASHUP 2015'. The background is black, which suggests a night-time or dark-themed setting, but the overall feel is more like a promotional or advertising material for a music video or a playlist.