Border Down (ボーダーダウン Bōdā Daun) is a horizontally scrolling shoot 'em up video game developed by G.rev and released in Japanese arcades in 2003. It is a spiritual sequel to Metal Black, a favorite game of creator Hiroyuki Maruyama. As with most other Sega NAOMI titles, the game was later released on the Dreamcast in September 2003 in two incarnations: a normal edition, and a limited edition that came bundled with a music CD and alternative cover art. Border Down was G.rev's second independent game (though they did subcontracted work on other titles, most notably Ikaruga and Gradius V), released after Sega's official discontinuation of the Dreamcast console.