Here is the full list of all 31 Gospel of Abaddon achievements.
Finish prologue
Get an upgrade item
Destroy 10 airplanes
Finish first level
Finish second level
Finish third level
Finish fourth level
Finish fifth level
Use all 9 magic items
Upgrade your airplane 100%
Finish all 5 levels without using magical stuff
Get 5 level
Get 12 level
Get 25 level
Finish 5 levels less than 5 minutes
Don't buy anything from the shop entire game
Don't use bombs entire game
Kill the boss without destroying any airplanes
Get all possible upgrade items in your room
Finish the game with 100% health or more
Make combo x20
Visit the twitter page of the developer
Visit the steam page of the developer
Destroy 100 airplanes
Destroy 250 airplanes
Destroy 500 airplanes
Destroy 1000 airplanes
Earn 10 000 money
Finish 12 deadly fights
Finish 25 deadly fights
Die one time to get this request