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