Here is the full list of all 18 Ion Assault achievements.
Complete a whole sector without dying once.
Completed the single player campaign.
Complete a regular stage without collecting a single Power-Up.
Finished a stage in less than 90 seconds.
Score exceeds 1,500,000 points (Campaign).
Destroy five asteroids at once.
Score exceeds 500,000 points (Campaign).
Survive 3 stages in a row without losing a life.
Destroy 50 big asteroids in a single game.
Destroy seven asteroids at once.
Get two extra-lives with a single score upload.
Score exceeds 500,000 points (Survival).
Score exceeds 1,000,000 points (Survival).
Score exceeds 2,500,000 points (Survival).
Score exceeds 5,000,000 points (Survival).
Score exceeds 10,000,000 points (Survival).
Score exceeds 3,000,000 points (Campaign).
Score exceeds 5,000,000 points (Campaign).