(I am now in a rush to test as many games as possible to help, so please do not mind the cursory reviewing style.)
Semi-on-the-fly remarks:
Controls ARE layout-independent!! :D (I have an AZERTY keyboard) (And arrow keys are also enabled.)
Did not know "Go Fish" (or forgot it?), so I went looking up the rules X)
Small bug: "You give him you As" written two consecutive times. Three times "You give him your 06s"; is this on purpose, actually? The plural made me think this should be written only once! Or the plural has to be removed.
Won barely by 7 to 6 right at my last turn! XD :)
Small bug: walking a bit (right then left), managed by chance to have the cards interface pop up only a split second! X)
Takeaway: very surprised by this take on the theme! Kind of a meta-approach, with a game inside the game (a concept which obsesses me, I have a big project based on this; and one of the possible constraints for the next Mini Jam (115) is this XD). As some others said, I think some more sounds would have helped make the game more pleasant. Nice choice to show the other prisoner as an anonymous black figure, too. I wish the gameplay was more than just almost exclusively the classic card game; in particular, it would have made the game feel even more personal, apart from the context.
Suggestion: I think you could have completely accepted your own approach and made a whole story/interaction side AROUND the card game, not just at the beginning! For example, something happens after and you can play with other prisoners, or some guard interrupts the card game, or helps the other or you cheating (in exchange for a bribe?), and so one. This would have been the occasion to have both more originality in the meta-approach AND add original mechanics! I feel you had a great initial idea with lots of potential, but did not fully develop it. I would encourage you to do so! :)