Here is the full list of all 87 DIG - there are Deep In Galaxies achievements.
Complete the tutorial
Kill a boss
Defeat the Overlord
Unlock the ninja
Unlock the hunter
Unlock the gangster
Unlock the engineer
Unlock the Fire Sector
Unlock the Alien Sector
Unlock the Casino Sector
Free the galaxy in 30 minutes or less
Unlock the doctor
Unlock the monk
Free the galaxy in 45 minutes or less
Free the galaxy in an hour or less
Free the galaxy without eating
Free the galaxy without buying anything
Free the galaxy in 'Freedom fighter' difficulty
Free the galaxy in 'Beacon of hope' difficulty
Free the galaxy in 'Galaxy liberator' difficulty
Finish the game with the bomber
Finish the game with the doctor
Finish the game with the monk
Finish the game with the hunter
Finish the game with the gangster
Finish the game with the alien
Finish the game with the engineer
Finish the game with the ninja
Inflict 1.000 or more damage with a ranged weapon
Inflict 1.000 or more damage with a melee weapon
Free the galaxy in 'True Overlord' difficulty
Inflict 1.000 or more damage with a super attack
Kill 100 enemies
Kill 1.000 enemies
Kill 10.000 enemies
Kill 100.000 enemies
Pick up 1.000 gold
Pick up 10.000 gold
Pick up 100.000 gold
Pick up 1.000.000 gold
Pick up 30.000 gold during a single run
Kill 500 enemies during a single run
Fire 10 projectiles with a single shot
Fire 25 projectiles with a single shot
Fire 50 projectiles with a single shot
Fire 100 projectiles with a single shot
Win the Jackpot at a slot machine
Open a Legendary equipment chest
Get two pieces of Legendary equipment from one chest
Get two pieces of equipment from one chest
Upgrade the content of an equipment chest
Meet Herr Keks
Eat a Holy Bread
Kill a hidden boss
Kill all enemies on a planet
Kill a lieutenant
Kill the Overlord without taking any damage
Kill a boss without taking any damage
Finish a mission without taking any damage
Get 20 skills in a single run
Unlock the chemist
Unlock the alien
Finish the game with the chemist
Free the galaxy in 'Rebel scum' difficulty solo
Free the galaxy in 'Freedom fighter' difficulty solo
Free the galaxy in 'Beacon of hope' difficulty solo
Free the galaxy in 'Galaxy liberator' difficulty solo
Free the galaxy in 'True Overlord' difficulty solo
Save the galaxy
Read a propaganda message
Survive a hit with 5 HP or less
Discover all the melee weapons
Discover all the range weapons
Discover all the skills
Discover all the biomes
Discover all the potions
Kill one enemy of each type
Discover all the equipment
Complete the encyclopedia
Discover all the classes
At least this was less frustrating than the other times you had to do so... right?
Discover all the sectors
Unlock the Galactic Slum
Reach the true ending in 'True Overlord' multiplayer without dying
Fight 3 rounds with your friends in Battle Mode
Finish Challenge Mode in less than 15 minutes
Finish Challenge Mode