Here is the full list of all 12 Laser Disco Defenders achievements.
Complete a cave with more than 50 lasers in it
Complete story mode with Liz
Complete story mode with Tommy
Complete story mode with Donna
Complete story mode with Mr. Baker
Complete story mode with all characters
Try out every outfit combination
Get to cave 14 in endless mode
Get to cave 21 in endless mode
Take out 1978 enemies over the course of the game
Pick up more than 10 hearts in one game
Survive 8 caves without taking a hit