Pretty Good
Here are some ideas:
1. Take out the blasted blood when people die. I don't see why everyone has to add this to Mario. Just go with the traditional death!
2. Make it so you can't jump through blocks to get on top of them. Also, sometimes getting on the blocks is tricky, as I fell through them quite a few times!
3. Giving Mario health isn't a bad idea, but maybe add in a mushroom that will help him regain it or something.
4. Power-ups! That would rock!
Overall a cool game, just needs to be a polished a bit more! I would recommend making it as close to the actual Mario game as possible.