Reversion - The Escape had Steam trading card support added on June 10, 2014. There are 9 cards in the series. The game originally cost $1, but later became a free game. If you purchased the game during the time it was for sale, you'll receive 5 card drops. Now that the game is free, however, its no longer possible for people playing the game now to obtain cards, other than purchasing them on the Steam Marketplace or trading for them.
The sequel, Reversion - The Meeting, also has trading card support.