Simplify the following text for a Grade 5 native English-speaking person.
Original: Spear of Destiny , a prequel to Wolfenstein 3D , was released a short time after the original game , using the same engine . A first person shooter called Rise of the Triad was going to be the sequel to Wolfenstein 3D , but the idea was postponed , and the game took off in a different direction .
Simplified: Wolfenstein 3D was one of the first first person shooter games .