These are the valid codes, 

  • jiro – Code reward: some in-game Gems (NEW)
  • derank – Code reward: some in-game Gems (NEW)
  • newyear – Code reward: some in-game Gems
  • mech – Code reward: some in-game Gems
  • xmas – Code reward: some in-game Gems
  • 100mil – Code reward: some in-game Gems
  • divine – Code reward: some in-game Gems
  • sorrygems – Code reward: some in-game Gems
  • spirit – Code reward: some in-game Gems
  • foxuro – Code reward: some in-game Gems