Here is the full list of all 11 Reed 2 achievements worth 1,000 gamerscore.
Get your first cube.
Die once.
Find the hidden character from Prisonela.
Find the hidden Duck.
Find the hidden Arcade Machine.
Find the hidden Horse.
Find about the Sword you can't pick up....
Find snow on a level.
Find the 1st hidden level.
Find the 2nd hidden level.
Find the 3rd hidden level.