Here is the full list of all 27 Avenger Bird achievements.
Get 100 rings.
Get 200 rings.
Get 500 rings.
Get 1000 rings.
Get 2000 rings.
Get 12 gems.
Get 20 gems.
Get 32 gems.
Get all rings from the first land.
Get all rings from the second land.
Get all rings from the third land.
Get all rings from the last land.
Get all gems from the first land.
Get all gems from the second land.
Get all gems from the third land.
Get all gems from the last land.
Finish tutorial.
Finish "Leap of Faith" without dying.
finish "Cannon Range" without dying.
Finish "Ice Climber" without dying.
It is very hard!
Tricky gliding for a park chest.
You are not worthy.
Get eaten by the second-dumbest creature in the universe.
If you could only walk through walls.
There's a switch that could help you.
Let's go home!