Here is the full list of all 12 XIIZEAL achievements.
Clear all stages without a continue.
The true game is just beginning.
Clear all stages.
Standing behind me will get you burned.
You're a long way from standing beside the likes of me.
Downed that fleeing plane at last.
Always wanted to drive a red sports car!
This one is the TRUE boss!
Three times as powerful!
Haven't I met you somewhere before?
Stage Clear when he flees.
It's been a while. Playing once in a while allows you to make new discoveries.