I think it would be awesome, PG-13 because of it's Fantasi violence and mild language (makes me think about Shadow using mild profane words like "Damn").
It'd be AWESOME! We'd have realistic-looking fights for once, assuming that hedgehogs can actually bleed. And Shadow would be able to swear and use Pistol again!
Why not? Blood isn't bad, despite what many parents may think. If anda fall and tear up your knee, you're going to bleed. That's just a part of life. There's nothing wrong with blood.