I tried that flow (oh, sorry, fl0w) thing once... I dodn't really get it, you just have to eat stuff and descend to the lowest level, were you had to eat a big thing so you could restart as a different creature or something? I really don't see the big deal about it, and usually I quite like alternative things.
As for interactive buddy, it's good while it lasts. It gets kinda old after setting him on fire 10 times. The rockets are fun, though, and the way he tries to run away from hand grenades after the first time you gave him one is also entertaining.