This was so much fun :) Loved the art style on both background and character sprites, and how the Morlocks altered in size and ragdolled on death. I loved the look of the Eloi too, poor things. The physics / destructibles were fun to play with, and rolling a boulder onto a pile or Morlocks was more satisfying than expected. Having the Keys / Morlocks / Eloi change location might help with replayability if desired. I'd love to see a little extended version of this where you interact with the Eloi outside the caves before facing off against the Morlock :)
Technically, switching the camera from left to right on mouse felt a little distracting.