Devil May Cry 5

There are a total of 12 secret missions and they can be found by red patterns on walls or floors. You have to line of camera to make that pattern complete which will send you into another dimension to complete. Most secret missions can easily be found by playing the game. They're out in the open but some are hidden well. The Trophy will unlock after clearing all 12 secret missions.

Secret Mission Objectives

01. Destroy all enemies within the time limit
02. Do not let any Red Empusa escape
03. Collect all of the Red Orbs
04. Eliminate all the demons without taking a hit
05. Get to the goal without touching the ground
06. Eliminate all demons within 20 seconds
07. Aim for the enemy's weak point, and take them down with a single bullet
08. Maintain an S Stylish Rank
09. Stay in the air for more than 15 seconds
10. Get to the goal without touching the ground
11. Maintain an S Stylish Rank
12. Collect a certain amount of Red Orbs

The following video, shows all the secret missions in chronological order:

All Blue + Purple Orb + Secret Mission Locations