Here is the full list of all 82 Steel Rain achievements.
Research all technologies in a category
Complete all missions on planet 8
Destroy 20+ enemy mines in formation C
Learn at least 1 skill of each firemode color skills
Learn your first active max skill of any firemode
Colonize all planets
Complete all Missions on Planet 7
Finish all Missions on all Planets
Hold your first million credits
Finish a stage using only formation B
Research and build a steel citadel
Complete all Missions on Planet 6
Finish 10 Quests
Finish a S ranked colony quest
Shoot your main laser for 1minute overall time
Finish a stage without taking damage
Place 100+ editor objects
Download a new stage from the workshop
Finish Stage in max difficulty
Finish a stage in hardcore mode
Build a harvester next to a trading hub
Build 10 or more Habitats
Complete all Missions on Planet 5
Hide your core and wings for a stealth attack from below
Complete all Missions on Planet 4
Research 5+ Technologies
Defend a colony from attackers
Visit the leaderboard area in the hangar
Reach core level 10+
Finish a stage without changing the firemode color
Complete all Missions on Planet 3
Finish a stage using only formation C
Research your first new Technologie
Evade enemy lasers in open formation C, with one wing on the left and one wing on the right side of the laser.
Evade 10 enemy lasers in formation C on the same height
Use the yellow firemode to convert credit drops into repair kits (Skill required)
Learn your first firemode Skill
Visit all Hangar areas
1000+ Kills
Finish your first colony quest
Finish Orbit Patrol Mission
Install 10+ upgrades
Complete all Missions on Planet 2
Collect 100 powerups
Repair 100 hull points
Get a drone pet
Reach core level 5+
First core level up
Hold 100k + credits
Finish your first construction
Install first upgrade
Colonize a planet
Complete all Missions on Planet 1
Finish a stage using only formation A
Reach S ranking
Finish Stage 1
Finish a 100+ combo
Finish a 50+ combo
Finish a 20+ combo
10000+ Kills
Reach core level 50
Share a new created stage
Create and share 4+ stages
Research all Technologies
Learn all firemode skills
Install all armor uprgades
Install all Firemode upgrades
Purchase all Drones
Purchase all Wings
Install all bomb upgrades
Play all 6 firemodes in each of the 3 formations
Purchase all upgrades
Finish all Planets in Max difficulty
Finish all planets in hardcore mode
Finish all planets in hardcore mode and at max difficulty
Install all missile upgrades
Find and kill the hidden bonus boss
Unlock and finish the boss mode
Finish the hidden boss encounter in hardcore mode and max difficulty
Finish a boss run in hardcore mode and max difficulty
Complete 3+ stages in legendary mode
Max out one of the elite skills