Great concept/demo, came here from reddit.
One quick suggestion: maybe re-skin health to hunger? So eating "reduces hunger" instead of "reduces health". Red's no longer heal; some reds are hollow and give less hunger (or have some special acid/poison that empties your belly). I found the concept of health going down when eating strange! I'd expect health to go down on "damage" things (like hitting itself, or hitting a wall/obstacle)