Full list of all 50 Guitar Hero: Metallica achievements worth 1,000 gamerscore. It takes around 50-60 hours to unlock all of the achievements on Xbox 360.
You earned a band Hot Streak
You completed the career in a band (2-4 player band)
You created a custom tattoo
You completed a song in every venue
You rocked out as King Diamond
You rocked out as Lemmy
You scored 575,000 on the song Creeping Death as the guitarist
You scored 450,000 on the song Dyer's Eve as the drummer
You scored 340,000 on the song Fight Fire with Fire as the bassist
You scored 1,000,000 on the song Battery as a band
Drummed every green note and finished the song Blood and Thunder with the rock meter in green
You hit every star power phrase in the song Orion
You got 100% on a song (4 player band)
You completed the Tutorials
You scored 65,000 on Stone Cold Crazy as the vocalist
You completed a song with all band members on expert in Quickplay or Career (4 player band)
You won a Band v Band match (8 players)
You played 20 online matches
You scored the highest individual score on a song in a band
You triggered star power simultaneously (4 player band)
You completed a song in a band in Quickplay or Career (4 players)
You won an online Face-Off match by 25,000 points or more
You won an online Face-Off match
You completed all the instrument careers
You completed the career as the vocalist
You completed the career as the bassist
You completed the career as the drummer
You performed as the vocalist
You earned 100 stars in Band Career or a single instrument Career
You completed a song at The Stone venue
You completed a song on Expert + in Quickplay or Career (drums only)
You earned $15,000
You performed as the drummer
You completed the career as the guitarist
You completed an instrument career on Expert
You completed a song at the Ice Cave venue
You performed as the bassist
You won a battle match with the Fade to Black power up
You downloaded a song from GHTunes
You won an online Pro Face-Off match by 25,000 points or more
You won an online Pro Face-Off match
You viewed a Metallifacts video
You completed a song in every In-the-Round venue
You recovered from a poor performance in Quickplay or Career
You scored 330,000 on the song Enter Sandman on guitar
You created a new custom band logo
You created a new custom rocker
You created a new custom instrument
You performed as the guitarist
You completed a song on Hard or Expert in local Quickplay or Career