I agree 100% with everything you've said. And I personally don't think it's rambling at all with the paragraph separations, and considering if it were my game I'd appreciate the feedback.
I didn't even realize there was a second section to the staff until the stronger magic/monsters started appearing. And the forest flipping mechanic I didn't realize until near the end, especially since earlier on it just blended with the drawing new cards and as you said it seems like an easy grab to avoid damage.
The tutorial part at the beginning could definitely be expanded upon to explain these. Perhaps the difference in the 2 staff positions could be noted or reasserted after you unlock the first level 4 potion, since that's when it starts to make more difference due to the bottom being limited to 3.
I also thought at first once the gems all greyed out I'd be dead, not at all clear that it revives them with one less until after it's happened once, which really changes the strategies you might employ when almost at the end.