Here is the full list of all 14 TWO MONTHS achievements.
Defeat Ban Slammer.
Defeat Roy T. Gillotti.
Defeat Stone Fist Chris.
Defeat Sorcerer Winfield-Pantoja.
Defeat Sebastien Chevalier LXXXVI.
Defeat Poison Pneuma
Reach "Good Enough" ending.
Reach "Perfection" ending.
Acquire all upgrades.
Acquire 9999 money.
Expand upgrade grid to 8x8.
Level up an upgrade to 10.
Complete Boss Rush.
Defeat Matzesu.