Great game loop! I really loved the visual style of the models and water, and being able to jump above the water was a great touch. I wasn't sure what to do about the toxic sludge, but I loved how it changes the environment to demonstrate its impact in real-time. It was cool to see a dedicated tutorial sequence and there was some nice feedback from destroying the trash. Some sound effects and music would be the icing on the cake.
Would be great to see the mechanics expanded-upon if you plan to develop it more in future!