Despite your being the badass pilot of various, often advanced, jet fighters through the series, at times Ace Combat still depicts the very concept of war as terrifyingly as possible, with the only way to sugarcoat them being making a lot of things implied. How the entire franchise (with the exception of Assault Horizon due to obvious presence of blood and human combatants in action and Infinity due to being an online game) got away with an equivalent of Everyone rating in Japan is anyone's guess...
In General:
- Some music tracks can be scary as well, such as "Silent" from Ace Combat 04: Shattered Skies or "Zero Sum" from Ace Combat 3: Electrosphere.
- With Ace Combat X: Skies of Deception being one of the hardest entries in the series, it comes as no surprise that the aerial warship featured in the game, "Gleipnir", comes with it's own terrifying theme as well.
- You can hear the enemy chatter over the radio, often sounding distressed and desperate as the battle starts to go against their favor, and when you strike ground and naval targets you may hear the sounds of emergency sirens going off while the personnel in charge issue evacuation orders. While it can make you feel like a badass whose mere presence strikes fear in your foes, it's also a grim reminder that at the end of the day, many of your enemies are humans who are just serving their country much like you are.
- Significant bosses often have intimidating themes backed by Ominous Latin Chanting to let you know that when they show up, things are really about to go south.