I'll agree that the jumping and running is fairly awkward compared to the ambitious and smooth grappling, sucking and slaying that happens in this game. I understand your speed is SUPPOSED to be slow when you're running out of blood, but quite frankly having a full bar of the red stuff doesn't seem to improve my agility THAT much. However, there's just too much good stuff going on to say this is a bad game.
The gameplay is incredibly varied, which is always welcome, and more so when it all happens with so few buttons. The enemies are very good, and strategy rapidly becomes top priority when facing them. You learn that you better not let 'em see you coming. You learn how to sneak up on them and eventually how to dodge most of their bullets and get them while they reload. You learn that you can not possibly beat two of them if they see you, but one you can handle. You learn where to hide, when to suck, when to cut, and when not to do those things.
Some things could be improved, of course. I found there's too many things you can do that aren't useful enough to learn to master them. Once you grab someone, for example, killing them with your blade is useless most of the times, since the only thing it achieves is avoiding being detected by other humans, and you can already do that by dragging your victim somewhere safe. Things like crouching mid-air or staying suspended between two walls happen too rarely, and only when the map is too obviously forcing you to do them. And, well, just to repeat myself, having a strong running speed when full of blood would've definitely resulted in a better experience.
Punishing the player with boring repetitive death levels, I don't know how I feel about it, but it sure as hell is original. In the world of casual flash games, infinite lives is a deep-rooted tradition, and we've seem many games that present basically no punishment for poor performance, except maybe going back a few tiles in the map. Now I'm not saying this is necessarily a bad thing, and believe me, restarting a screen in this game feels already like enough punishment, but the death levels are a curious feature that I'll deem good just because of its originality. Just make sure next time the punishment is less boring.
The story, for what little there is, is pretty good. I would only complain about the fact that some key facts get stated during the introduction and are too easily forgotten when you don't repeat them. By the ending, for example, I had forgotten about Elly's gender, about her ally's fire-like nature, and also about her promise to him. So when the end sequence began, I didn't understand which lines belonged to my enemy and which to my ally. Maybe some indication would've been better, like the name of the character speaking before every line? And also, some reiteration of the main plot throughout the levels? I don't know, really.
The bosses were HARD, but fun and very rewarding. The first one, at least, seems hard enough to make a lot of new players rage-quit, so making the difficulty a little more gradual would've surely been welcome. The ending (SPOILER) I didn't quite get. It was a nice turn of events when Elly's enemy chooses to spend his last words giving her, his murderer, advice, and it is very climatic when her ally appears in the form of the rising sun, and when she actually follows her dying enemy's advice and breaks her promise with just a few seconds left, but there's not enough explanation as to why does she do that. What does she gain by not letting her enemy die in his old rival's fire? And what does the last image represent? Is that a Christian cross, like in a tomb? Whose is it? Well, I guess it's not really all that crucial.
Anyway, a truck full of congratulations to you for such a nice, engaging game.