Cool idea. I think it´s very unique and has a lot of potential. It´s fun to place down a lot of mines and see all the enemies exploding. I would make it that all enemies on the mine explode and not just the one that triggered it. I love your art style and especially the run animation :).
I would also put the health- and the manabar over the player so they are easer to see.
Overall a great game. Good Job!