"A Midsummer NMIXX's Dream" is the third single album by NMIXX. It was released on July 11, 2023 with 4” tracks including “Party O'Clock" as the single's title track. A Midsummer Nmixx's Dream consists of four tracks. The first track and lead single "Party O'Clock" was described as "garage-based" pop song known for its "bright and exciting melody". "Roller Coaster" described as an urban house song with a dreamy pre-chorus and a summer vibe.

Tracklist:

1. Party O'Clock
2. Roller Coaster
3. Party O'Clock (Inst.)
4. Roller Coaster (Inst.)

Inclusions:

• Package : 130 x 130 x 5mm
• CD
• Postcard Photobook : 20p
• Photocard : Random 1 out of 12