Full list of all 13 Boomerang Fu achievements worth 1,000 gamerscore.
Kill an opponent after dying
Master the disguise powerup
Telefrag an opponent
Get killed by one of your "teammates"
Kill many opponents with the telekinesis powerup
Dodge a lot of boomerangs
Regularly kill yourself with the explosive boomerang
Kill a lot of enemies with fire
Shatter a lot of frozen enemies
Squish several opponents with moving blocks
Kill opponents while unarmed
Spend a lot of time hiding in the bushes
Be on time to things