Here is the full list of all 21 Retro War achievements.
You have removed a total of 1000 ships.
You have removed a total of 5000 ships.
You have removed a total of 10000 ships.
You have played for 15 minutes.
You have played for 30 minutes.
You have played for 1 hour.
You have died 100 times.
You have died 200 times.
You have died 300 times.
You have completed the world 1.
You have completed the world 2.
WORLD 3
You have completed the world 4.
You have completed the world 5.
WORLD 6
You have completed the world 7.
You have completed the world 8.
You have completed the world 9.
You have completed the world 10.
Get 3 stars on all levels
Reach stage 20 in infinity mode