Here is the full list of all 27 Sky Force Anniversary achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Earn 100 medals.
Collect 200 000 stars.
Save 20 000 stars in your bank.
Ram through an enemy wave with your Energy Shield.
Destroy at least 15 enemies with one Mega-Bomb.
Burn through 10 enemies with your Laser.
Finish a stage with your health lower than 5%.
Rescue your friends 20 times.
Rescue 5 VIPs.
Find all the cards.
Collect all the stars from Stage 3.
Complete Stage 8 without using power-ups.
Collect 100 000 stars.
Use 3 different power-ups in a single game.
Save 5 power-ups at the end of the stage.
Use any 5 power-ups in a single game.
Rescue 1 000 people.
Earn 50 medals.
Destroy 10 000 enemies.
Rescue 500 people.
Destroy all enemy towers on Stage 5.
Earn 10 medals.
Destroy 2 500 enemies.
Rescue 100 people.
Enter the tournament.
Destroy 1 000 enemies.
Destroy the lighthouse without touching it.