The character art is incredible, the cat has a lot of personality. I was pretty immersed in finding out how all of the cave explorers died.
The cat's dialogue box is anchored to the world so I had a hard time reading it all... I get the feeling my issues not being able to go fullscreen in firefox are preventing me from seeing some stuff. Once I got to the glowing mushroom the visuals seemed very low-res.
I only realized I could double-jump when I tried to reach a high ledge early on.