Thanks for playing and for the feedback!
I tried to make the enemies progressively stronger and harder to beat, but I couldn't manage to balance the game very well in the time I had. However, improving the game's difficulty and making it more fun is definitely on my list after the jam ends.
And yes I agree, the lack of sounds is a big disadvantage. I've postponed it too much and I couldn't add them in time.
And again, thank you for the feedback! I absolutely had a lot of fun making it and I learned a lot!