Thanks a lot for playing! I think you are the first one that reached the end, congrats!
The game truly is in need of more polish and especially a more intuitive UI. I put in some blinking animation to the portraits to make the player click it after a level up, but apparently thats not enough :D
You are absolutely right about the potion counter, thats planned. Currently those buttons let each companion drink a pot if their health/mana is below a threshold (so they don't uselessly drink all of it). An easier way to force a potion on specific members could be great, but hard to do in an intuitive way.
Skill trees were also a first draft the way they are now. Choosing a new tree for the MC was a bit hacky. This whole thing needs more thought and work.