Not going to lie, the player healthbar completely slipped my mind at least. We were having some issues with getting the player to even take damage, and by the time that was fixed I had forgotten about the healthbar to show that fact.
The walking on water thing was mostly because we were struggling to come up with level ideas and sewers was basically the best thing we could think of. In our minds, we figured that the water would be pretty shallow, but necessary for the image of a sewer. I suppose that's not immediately obvious if you're not part of the design prossess though.
This was personally my first time using unity so I'm mostly pleased that it even runs, but I'm glad you enjoyed it dispite the problems.