Aphelion Cosmetics DLC includes the following exclusive cosmetics:

• Backpack sticker: Lost Records: Bloom & Rage – Eyeball
  
• Backpack sticker: ESA – Friends in High Places
  
• Backpack sticker: Jusant – Climber
  
• Backpack keychain: Lost Records: Bloom & Rage - Three-eyed Cat
  
• Backpack keychain: ESA – Hope-01
  
• Backpack keychain: Jusant-Ballast
  
• Digital artbook
  
• Digital Soundtrack
  
• Space Pioneer – ESA alternative suit
  
• Space Hero – a suit worthy of a space opera

You can select your cosmetics through the main menu at the start of the game.