The DLC Set 4 Add-on for R-Type Final 2 has 4 achievements.
Re-experience II: records of a battle with aquatic creatures on the Second Bydo Mission.
Special Mission: battle records from the virtual space that has materialized due to Bydo pollutants.
Re-experience II ends with the Diffusion W. Cannon defeating a giant Bydo in the grotto's depths.
You completed the special mission by firing over 20 Pod shots at ships on BYDO difficulty or higher!