Rock to the Rescue! Trophy in Rock of the Dead
Rock to the Rescue!
Finish the game and get the good ending.
How to unlock Rock to the Rescue!
You will know you are near the end of the game for this once you get to the Brainwashed! level. You'll be given instructions on what the monitor colors mean, and how the ending might entail. To get the good ending, you'll want to change all the red monitors to green by correctly hitting the applicable notes on the monitors in the allocated amount of time. If you are too slow, you will take damage and start from the beginning of that sequence again.
After you made the choice, you will proceed to progress to the final level. This will unlock upon conclusion of the game.