Pretty art and I like the concept of the game. I think more effects based on temperature would be very interesting (such as lowering temperature to block a strong fire attack). Also, it'd be nice to have more enemies with lower health so we can ease in into the mechanics of the game.
I got used to it and came up with a strategy to win against the enemy, and that was fun, I think this idea has potential after ironing out some kinks.
I think the current music gets in the way of the gameplay after some time. Also, I think it could change based on the current state of the fight: a chilly music when the temp is cold and a faster, more intense one when the temp is hot.
Other than that, good job!