Very fun concept! Managed to defeat the second enemy on my second try... And only figured out I could rotate items afterwards!
I liked how the amount of items you receive, was higher than what you could handle. It enforced me to prioritize between attack and health, but also allowed me to keep juggling items by dragging them back to the top of the screen. I think the juggling would be an even better mechanic if some items in the backpack would be consumed after use (for example, a potion that heals instead of increasing total HP). Then the player could keep juggling items to restock his backpack after a consumable was used up. This would also add something to do during a fight with an enemy, which was currently passive.
I enjoyed the color palette of the game and the music was soothing.
The text log felt a bit useless since you didn't have time to look at it during gameplay anyway, but it was a nice touch to read during downtime.
All in all, fun idea and great execution!