A new weapon, the Paintinator, is also included in the level pack. However, those who don't buy the pack will still be able to experience it, either by joining an online host that's playing it, or by playing any of the user-made levels that include its content.
"Now you won't be able to keep any objects [you earn playing the Metal Gear Solid levels online if you don't own the pack], but you can have tons of fun just playing," SCEA marketing manager Mark Valledor explained on the official PlayStation.Blog.
Meanwhile, the costume pack includes Solid Snake, Raiden, Meryl and Screaming Mantis outfits, which can be bought together for $5.99 or separately for $1.99.
Both the Metal Gear Solid Costume Pack and Metal Gear Solid Level Pack will be available through the online PlayStation Store beginning Tuesday, December 23.