The art is very beautifull with an unique style and awesome transitions. The music fits the game too.
The gameplay give an impression of speed, which is good. But when going at full speed it's almost impossible to dodge anything. Offseting the player character to the left of the screen would give more time to react. Increasing the contrast of the fireball vs the background would make them easier to see too (the blue background of the ground level work well for that).
Also there a lot of things are unclear. I'm still not sure how the health system works, showing health points would help. The green orbs looks like the fireball but it seems that they are not hurting the player (heal??). It look like we have to go fast because Zeus is closely following, while in reallity it's possible to stop or even goind back and he will stop too. Also I tried a more carefull/slow approach, that get me farther than the fast one, but I died suddently without apparent cause (no fireball, no zeus, no falling). Feedback (sounds notably) would also help making the things less confusing.
Good job anyway, it's one of my favourite game in term of art and "mood". Lot of potential here, just need a more polished gameplay.