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