Nice game! As a card-game player, this one is a really creative one. Like a "Battleship" in format of cards! Unfortunately, the game is a little too based on luck, which is, generally, not a good thing to have in a game. But, for a jam game that is played against the computer, it's totally fine!
The "!!!" alert to make you think better before attacking is a good way to try to compensate to luck base.
The art and music for the game is nice too, really neat!
Had a good time playing it. Congrats!!