Make sure to install the DLC prior to following this guide!
Easy enough. Pass all 8 main game levels and you’ll unlock these achievements.
DLC Scene Achievements
6 missions have a DLC scene associated with them. Watch the scene for each associated mission to get the achievements.
Other than killing the boss at the final level, the rest of these are Kill X enemies. You should get all of these just by playing through the 8 missions.
These can be done in the bottom-left DLC on the mission select screen. You can choose either character, any music, and any motion. Press the Spacebar to take a picture.
NOTE: Spamming the spacebar will not register each photograph. You need to take a photo and then wait for the menu options at the top right to reappear (it’s fast) before taking another photo or it won’t count to your total.
DLC Date Achievements
These can be accessed via the bottom-middle DLC option on the mission select screen. Each character has 4 routes you can take. Go through all 8 and you will unlock each of these achievements.