Here is the full list of all 35 Defend Felinearth achievements.
Clear all level on Normal or higher with A rank or better
Clear all level on Hell with S rank
Clear a level on Hell with rank S without using any skill
Clear a level using only main weapon
Clear a level on Hard or higher without taking any damage
Get a combo amount above 200 in Survival
Defeat 300 enemies on Hard or higher in Survival
Defeat 3 enemies by one dash
Defeat 5 enemies by one explosion
Defeat 3 enemies by one laser
Stay alive for 20 seconds in Crisis Mode - Hard or higher
Revive from Crisis Mode 3 times in one level - Hard or higher
Unlocked all ships
Unlocked all sub weapons
Unlocked all skills
Clear all EX level with Samurai Edge
Clear all EX level with Deadly Violet
Clear all EX level with Wind Ninja
Clear all EX level with Crimson Serpent
Clear all EX level with Bubble Storm
Clear all EX level with Kraken
Clear all EX level with Silver Lancer
Clear all EX level with Heaven Guardian
Clear all EX level with Vulcan
Defeat a boss while it is dashing in level 1-1
Get out of boss' ring in level 1-2
Defeat a boss while you are spinning in level 1-3
Defeat a boss while it is invisible in level 1-4
Defeat a boss without breaking its shield in level 1-5
Avoid a cross explosion in close range in level 2-1
Stop boss' explosion in level 2-2
Escape from black hole without using dash in level 2-3
Defeat a boss with the last shot in your magazine in level 2-4
Defeat a boss using only main weapon in 2-5
Defeat a secret boss while you are blinded from its flash