Very cool idea. Although I might be biased, since I made a game last year where you could play as monsters, too. (Not saying you "stole" it or anything, it's not like I was the first to put possession in a game.) I like the fact that eating the meat of your enemies gives you their powers, too. I think I've seen that mechanic used somewhere before, but not to a very large extent...someone should make a 7DRL with that as the central mechanic...but now I'm just rambling.
I only played a bit so far, but I plan on coming back later. The one problem I did see is that the game never seemed to get keyboard focus, so if I pressed up/down the page scrolled up/down too.