Nex Machina

To be able to play master difficulty, you’ll need to have completed the game on veteran first. Knowing you’ve completed the game on veteran this trophy shouldn’t be too difficult for you to obtain. The major difference between veteran and master is that every enemy you kill will shoot a projectile back at you. You’ll definitely want to strafe in circles around the enemies as this will make the projectile miss you. Other than that, Beamtron will have a few new tricks up his sleeve, but you’ll easily have the hang of this boss in a mere couple of tries.

See the video below for visual reference for the trophy. It definitely isn’t perfect as it was my first attempt at it.