The game is initially in English. In the base game there are 37 cards that are language dependent (most of them only have a couple of lines of text though).
Once we reach 200 backers that want the game in a single language other than English, we unlock the $2 add-on that allows you to get the 37 language dependent cards of the base game (plus any other language dependent cards unlocked through stretch goals).
If you want to count for the 200 backers needed to unlock another language, please state so in the comments or in a message to us. We will keep a tally of the backers in the different languages in the "Rewards" section, that we will update every day or so. Once a language gets its 200 backers, we will do an update so everyone knows!