Here is the full list of all 20 BATSUGUN Saturn Tribute Boosted achievements.
Complete Stage 3.
Increase your level to 3.
Complete Stage 2.
Increase your level to 2.
Complete Stage 1.
Don't let a plane take off in Stage 2.
Complete Stage 4.
Complete Stage 5.
Complete Round 1 (Special Ver.).
Complete Round 2 (Special Ver.).
Complete Round 3 (Special Ver.).
Complete Round 4 (Special Ver.).
Earn 1,000,000 points with secret pigs.
Fill one experience gauge up with purple secret pigs.
Collect 100 small Vs in a stage.
Collect 50 big Vs in a stage.
In the original version, make a score of 1,000,000 points.
In the original version, make a score of 2,000,000 points.
In the special version, make a score of 5,000,000 points.
In the special version, make a score of 10,000,000 points.