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