Nice little game. Like others have already said, the visual feedback would have made the experience much better.
This is for your next Game Jam. In general, such games, where you fight constant mazes of enemies, you want the HIT feeling to be one of the first things you design properly, because this is what your player will be seeing and interact with the most.
It could become a full game with enough work, just keep in mind that the market is full of similar games, so you will need to think of more ways to make the experience unique!