Currently 12, (not counting Metroid Prime: Trilogy and Zero Mission), and one unreleased, which is Metroid: Other M (making number 12). The chronological order of the games are: Metroid/Metroid: Zero Mission. (Zero Mission was a remake of the original Metroid) Metroid Prime/ Metroid Prime Pinball Metroid Prime: Hunters Metroid Prime 2: Echoes Metroid Prime 3: Corruption Metroid II: Return of Samus Super Metroid Metroid: Other M Metroid: Fusion *Note that these are NOT listed by release dates*
Metroid Prime Pinball - 2005 VG was released on: USA: 26 September 2005
Cinematech - 2002 Metroid Prime Hunters 5-8 was released on: USA: 13 March 2006
Metroid Prime Hunters - 2006 VG was released on: Japan: 20 March 2006 UK: 20 March 2006 USA: 20 March 2006
Harlem Echoes - 2008 was released on: USA: 1 January 2008
Distant Echoes - 1999 was released on: USA: 6 June 1999
Echoes of the Past - 2005 was released on: USA: 9 September 2005 (limited)
Echoes - 2006 I was released on: USA: 29 March 2006 (Sacramento Film Festival)
Captain N The Game Master - 1989 Metroid Sweet Metroid 1-12 was released on: USA: 25 November 1989
Echoes That Remain - 1991 was released on: USA: June 1991 (Los Angeles, California)
Journey of Echoes - 2011 was released on: USA: 8 September 2011 (Los Angeles, California)
Broken Echoes - 2004 was released on: USA: March 2004 (Washington D.C. Independent Film Festival)