Only one real change: the player character changes color based on the percentage of remaining hit points.
White = 100% HP
Yellow = 99-51% HP
Orange = 50-26% HP
Red (and warning message) = 25%-0% HP
I realized today that this is a feature several major Roguelikes have to varying extents and one that I'm a big fan of. So the obvious thing to do is implement it shamelessly! There may be a couple of minor oddities because your hit points won't always divide cleanly, but it should (in theory) work fine otherwise.
I always put these links up even though there are persistent links on the sidebar.