Signal Ops had Steam trading card support added on November 18, 2013. There are 6 cards in the series, 3 of which you'll receive for purchasing and playing the game.
Trading Cards
Foil Trading Cards
Badges
Level 1
Staffer
Staffer
Level 2
Officer
Officer
Level 3 Director
Level 4 Shadowy Figure
Level 5
Emissary
Emissary
Emoticons
:arrest: (Common)
:boned: (Common)
:look: (Common)
:pie: (Rare)
:scope: (Common)
:plus: (Uncommon)
Profile Backgrounds
Interrogation (Common)
Characters (Uncommon)
