Here is the full list of all 50 PLANETS OF WAR achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Check The Pause Menu
See The Credits
Finish The Game
Kill The End Boss
Start Level 4
Destroy The Alien Planet
Destroy The Enemys Spacestation
Destroy The second Mothership
Make 2000 Hits
Start Level 3
Destroy an asteroid
Destroy The First Mothership
Make 1000 Hits
Start Level 2
Make 500 Hits
Change The Firemode
Make 250 Hits
Make 200 Hits
Make 100 Hits
Make 50 Hits
Make 5 Hits
Kill a Enemy
Start Level 1
Check the options
Start The Game