The saga of AstroN goes on with the progress of the stages you clear. There is a final target(boss) in each stage and you will be rewarded after you complete each mission.
Stage1 - Planet M1
This place is of great importance for the people of Acron. It's one of the sanctuaries dedicated to their God, Rahkiel. Lord Traticera appears from time to time and ruins the holy place of Acron.
A stage fit for an apprentice pilot.
Stage2 - Planet M2
General Zavos of Bellico plots to make bad blood between the two major enemies: Acron and Shrewdo. He plans to decoy the sacrificial monster of Acron, Delgaido, into the zone M2 which is the Shrewdo territory.
Stage fit for a rookie.
Stage3 - Planet M3
Ancient relic of Shrewdo presumably devastated by the Neutron Bomb of Acron. Acron is sending in the elite troops to delete all evidence that could lead to their previous deed.
A stage fit for an intermediate pilot.
Stage4 - Planet M4
The place is where a secret lab assumed to be Acron's is situated. Acron lost control over the facility long ago and it is now filled with vile, unknown creatures.
A stage for an advanced pilot.
Stage5 - Planet M5
Mechanic units invade the transport bases of all three species. The three nations suspect Mechan's return and send in a large number of back up forces to protect the facilities.