hm. not bad, but it could be better. Some things you can improve:
-The principal objective is get better and give it to the gray box, the gray box is a important thing, you could have done it more flashy to highlight more the objective.
-the enemies drop so much gold and make the game so easy.
-When the enemies hit me, i dont feel anything. You could improve that adding a knock to the player, or a sound or something to warn me that the enemy hit me.
but despite that it is fun to play, good job ^^