This main game, released in 2009, is a foundational rhythm title centered entirely on the music and virtual performers of the Vocaloid software, most notably Hatsune Miku. Gameplay requires players to execute precise button presses synchronized with on-screen prompts matching the song's beat and melody across various difficulty levels. Its distinctive feature is its direct integration with the established Vocaloid music ecosystem, offering a unique library of tracks and customization options, with base content expandable via available DLC.
The primary gameplay loop involves hitting corresponding face and shoulder buttons in time with visual prompts that scroll across the screen, matching the beat and melody of the featured tracks. Success is determined by the accuracy of the player's timing, which affects their score multiplier and overall performance rating for the song. The game features various difficulty settings, allowing players to tailor the challenge level to their skill set.
As a Main Game, it establishes the foundational mechanics that define the series, focusing on rhythm execution and visual presentation tied directly to the music videos accompanying each track.
The atmosphere of the game is bright, energetic, and deeply rooted in Japanese pop culture, specifically the digital music scene that birthed the Vocaloid phenomenon. While there is no traditional narrative storyline, the game's setting is the stage itself, where players interact with Miku and her associated characters through various song performances, unlocking new costumes, modules, and music tracks as they progress.
The defining feature of this title is its exclusive reliance on Vocaloid music and its virtual performers. Unlike many contemporary rhythm games that feature licensed music or original compositions by internal studios, this game serves as a direct portal into the established, user-driven ecosystem of Vocaloid songs. This provides a unique library of content that is instantly recognizable to fans of the software.
The initial release includes two downloadable content packs (DLCs) that expand the available song list and customization options for players who wish to extend their experience beyond the base game offerings.
While the original release was exclusive to the PlayStation Portable, a related downloadable title was later made available on the PlayStation Network for the PlayStation 3, offering updated visuals for the same core content, provided the PSP hardware was connected to the PS3 console.

Hatsune Miku: Project DIVA Mega Mix Song Pack 12 includes: - Out of Eden - Innocence - slump - Absolunote - Meiteki Cybernetics - Disruptive Diva - Zigg-Zagg - Sayonara, Goodbye - Equation+** - Here Comes Karakasa-san

Hatsune Miku: Project DIVA Mega Mix Song Pack 13 includes: - To the End of Infinity - Requiem for the Phantasma - Oha-Yo-del!! - That One Second in Slow Motion - Gothic and Loneliness ~I'm the very DIVA~ - How'd It Get To Be Like This? - Nightmare ☆ Party Night - One-Sided Love Samba - Iya Iya Seijin - The Star Maker

Hatsune Miku: Project DIVA Mega Mix Song Pack 14 includes: - Far Away - Song of Life - moon - Francisca - Butterfly on Your Right Shoulder -39's Giving Day Edition- - Wolf Girl - break;down - Hanamai Tsukuyomi Tan - Mellow Yellow - Updating My Love List?

Hatsune Miku: Project DIVA Mega Mix Song Pack 15 includes: - Jaded - Dear cocoa girls - Transparent Watercolors - Time Limit - Solitude's End - Now Choose - Master of Puppets - Symphonic Dive - Diva FT edit - - Jugemu Sequencer - Step Forward - So Much Loving You★ -Diva Edit-

Hatsune Miku: Project DIVA Mega Mix Song Pack 16 includes: - Dreaming Leaf - Song of Eternity -DIVAMIX- - Holy Star -2010 DIVA mix- - Rain With A Chance of Sweet*Drops - Pane dhiria - maigo life - Soiyassa!! - Beware of the Miku Miku Germs♪ - Perico Space Shipper - Dance of Many

Hatsune Miku: Project DIVA Mega Mix Song Pack 17 includes: - melody... - The Two of Us - Futaride - Pink Moon - Magical Sound Shower - Betty The Liar - Idol Radio (Game Edit) - Starlite★Lydian - Love's note - Gizmo - Kagamine HachiHachi Flower Fight

Hatsune Miku: Project DIVA Mega Mix Song Pack 18 includes: - Senbonzakura - Knight of Light - High School Days - Diva Edit - Kimi Ni - Let Me Lose Myself in The Black Note - I Really Do Understand - Lucid Dreaming - A Song of Wastelands, Forests, and Magic - Velvet Arabesque - Travel to The Other Side of The Moon - Iroha Uta

The second Hatsune Miku: Project Diva DLC was released by SEGA on the PSN Store on 1 July 2010. It featured 18 songs sung by Kagamine Len/Rin and Megurine Luka (2 songs by Len, 7 songs by Rin, and 9 songs by Luka), high-quality polygon PVs of all the songs, 'Toeto' Luka minigame, and special Len/Rin and Luka themes for PSP XrossMediaBar (XMB) menu.

Hatsune Miku: Project DIVA Dreamy Theater is an enhanced port of the PlayStation Portable game Hatsune Miku: Project DIVA. It was released digitally for the PlayStation 3 on 24 June 2010.

The first Hatsune Miku: Project Diva DLC was released by SEGA on the PSN Store on 25 March 2010. It featured 9 songs sung by Hatsune Miku, high-quality polygon PVs of all the songs, "*Hello, Planet" 8-bit minigame (featuring 4 levels), and a special Miku theme for PSP XrossMediaBar (XMB) menu.