Find a secret area.
Beat a level without dying.
Kill 50 enemies.
Get at least 20 stars in the campaign.
Complete 5 levels without firing a shot.
Kill all enemies in 5 levels.
Get at least 40 stars in the campaign.
Try each of the arcade modes at least once.
Find all secrets in the campaign.
Get at least 60 stars in the campaign.
Beat every level without dying.
Get at least 100 stars in the campaign.