Very strong core mechanic
Althought I can't fight the feeling that, this game lack a few tweak to make it perfect. It fell a bit too random, the game should be more about the player's ability to make quick and meaningfull decision. Here are some suggestions to improve this.
1. Make sure the shrines don't appear if the life spane isn't below 50%, then increase the appearance rate as the lifespawn goes down.
2. Make a different icon for Dragon/boss encounter.
3. Add a way to skip phase, if I can't buy an item it should not be there for 5 seconds.
4. Why not make it so that every day is a new item instead of forcing the player to buy them all ?
5. Make the appearance change when buying armor and weapon.
6. Make sure to not have sequence like; elixir, armor, elixir,elixir. Or maybe simply have some small amount of money for each each.
7. Remove/Fix the delay between event in current window and enabling the click action.
8. why not a key, and treasur chest mechanic, find a key decide to to use it on a chest or keep it for ater.
9. Equipment is nearly unreable, ther is no reason to hide the titles.
10. What about when low on life span or hp, character's attack increase and/or speed double?