From what I understand, the game is endless. I think you did a great job implementing the theme, and I really enjoyed it.
One piece of feedback: I didn't hear a damage sound when the player got hit. The slime turning red is good visual feedback, but adding a sound effect would make it feel much more impactful.
I also have a gameplay suggestion. It could be interesting if the player could sit on a chair and hold S to rest and recover health more quickly. To keep it balanced, resting could also make the enemies stronger or increase their level, adding an extra layer of challenge. As it is now, the game isn't too difficult as long as you don't get overwhelmed by too many enemies at once.
Overall, I enjoyed it. Great job, and congratulations!