I liked this one and think there's definitely a lot of potential for cool gameplay here. (I may sound a bit critical with my thoughts here but I did like it!)
The speedy blood is cool, but I feel like it could have been better appreciated if more of the game design encouraged it. For example, maybe a bigger stage would have encouraged painting the screen with blood since it'd be necessary to get around. Perhaps bigger blood splats would also make it easier to fill up the screen and get into the core gameplay of dashing around the level. Also, maybe enemies could get faster over time, which requires you to use the blood splats, not just use them for a bonus.
Yeah, seems like all I have to say is could-have-beens, but all that means is that I liked the idea a bunch and wish I could have seen more! :)