Since it's a visual novel first and foremost, the card game acts as more of a simple feature/mechanic to help pace and add an extra gameplay loop into the mix that ties the theme of romance together.
Programming a complex TCG would be very hard to do in the game engine as a solo/small team and if we did, we wouldn't worry so much about the visual novel aspect that we wanted to focus on. Thanks for your input and glad you still like it for what it is!