The blood potion prefab wasn't tagged with the "interactlayer" layer but that's now fixed (it was actually one of the first things I fixed after I submitted).
I'll take a look at the elixir bug too!
Optimisation is a must, but it is more about the stupid high settings the game shipped with. As I said now I have more than double the frame rate but there's always room for improvement.
I'll re-evaluate the combat mechanics too!
Stay tuned for the boss fight, as this is also planned!
Thank you again for your time and feedback.