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