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