Here is the full list of all 37 Steredenn achievements.
Finish the game once.
Finish the first loop.
Beat the game using the Blaster only.
Destroy the Nemesis.
Meet the Mothership.
Destroy the Mothership.
Destroy a Battleship boss.
Destroy a Carrier boss.
Destroy a Cruiser boss.
Destroy a Destroyer boss.
Kill 1000 enemies.
Kill 500 fighters.
Pick 15 differents weapons.
Destroy a Frigate boss.
Kill 250 enemies.
Destroy a Bomber boss.
Kill 50 enemies.
Kill 2500 fighters.
Kill 10000 fighters.
Destroy 100 cargos.
Kill a spy with the flamethrower.
Pick all weapons at least once.
Pick all Energy weapons.
Pick all Bullets weapons.
Pick all Heavy weapons.
Pick all Bots weapons.
Pick all Melee weapons.
Defeat all the bosses in the Arena at least once.
Dies 50 times.
Try all upgrades.
Destroy the Alien ship.
Destroy the Old Friend.
Destroy the Garbage Collector.
Destroy the Astroworm.
Beat the Red Baron
Destroy the Super Chabal.
Complete a boss rush.