Here is the full list of all 15 Astro-g achievements.
Restart 200 times.
Enter 500 gravity zones.
Enter 150 gravity well zones.
Enter a gravity well zone.
Enter 400 repeller zones.
Complete Galaxy 1.
Complete Galaxy 2.
Complete Galaxy 3.
Complete Galaxy 4.
Set a new record.
Reach the maximum consecutive bursts from launchers.
Complete Debris Field touching only launchers.
Reset via going out of bounds.
Put your ship into uninterrupted motion for 20 seconds.
Have your ship collide with three different dead planets in one shot.