The player may destroy them for 10 points each.

After the player has destroyed every enemy that is on the grid, a number will be indicated.

In the final section, the player must destroy a "base".

At the end of each stage, the player must destroy a boss vehicle to proceed.

The players can also destroy each other, after which they "respawn".

The player must move to that door and destroy the bomb with gunfire.

To clear a level, the player must destroy all of the blocks.

To clear each attack wave, the player must destroy all enemy vessels.

The player(s) must destroy every doll to complete the level and move to the next one.

The player must destroy the enemy bases, then go after the space station itself.