Quite lovely! I was already intrigued by the title, since Schlonk just has a ring to it :D The sprites and artwork are super nice, especially the characters/monsters. Something didn't feel 100% cohesive with the ground texture, but I'm not quite sure what it was. Music/Sounds in themself were also great, maybe the music just needed a bit more of variety, since the intensity was pretty high all of the time. Gameplay was very enjoyable and easy to grasp, just the enemy hitboxes felt quite finicky sometimes, especially while using the tongue attacks.
All in all really impressive! Great job!