Here is the full list of all 22 STARWHAL achievements worth 1,000 gamerscore.
Obtain 30 Bronze medals in challenge mode.
Die 100 times in challenge mode
Die 1000 times in Challenge Mode
Beat your ghost.
Get your first platinum medal.
Get 20 gold medals in challenge mode.
Get your first gold medal
Get your first Bronze Medal
Obtain 15 Platinum in all Challenges
Get your first silver medal
Obtain 25 Silver medals
Obtain 32 Platinum medals
Accumulate 4096 total points in Score Attack
Taunt 25 times in a single match
Shatter 1000 blocks of Ice
Hold a Zone for 45 consecutive seconds
Win a Versus Heart Throb match being the sole holder of the Heart
Play 1,000 rounds of Versus Mode
Play 1000 rounds of Versus
Stab 1,000 hearts in Classic mode
Stab 3000 hearts in Classic mode
Accumulate 2,000 total points in Score Attack