An interesting concept, but I think it's a bit rough around the edges. I like the idea of memorizing the runes in order to cast them. Although, if this were to be implemented on a larger scale, then some kind of grimoire or notebook where you can lookup spells you already know would be important to have.
What I liked:
1. The aesthetics look lovely and peaceful
2. The idea is new and interesting
3. The background music fits the theme well
What I didn't like:
1. Very little explanation on how the runes selection works
2. No feedback when the player is hit (audio and visual queues would help)
3. Lack of explanation of what each spell actually does
Other things I found and suggestions:
1. You can sometimes jump again while in mid-air (This is not related to the second spell where you can double jump)
2. Having some kind of notebook that saves all spells you learned would really help
All in all, nicely done.