Thanks for playing and making such full feedback!
"the feeling of "old PC disk" games" - yes, that's exactly what I was aiming for (and many issues might be connected to how I remember that era). Sadly my experience with making platformer like games are quite limited, particular to this one, but that's why I wanted to try and make it :)
For control scheme, it sound logical in my head, G for gravity boots, H for healing, P for tome of power. I understand it's too stretched over the keyboard, though was not something unbearable during playtests. Enter for dialogue - I regret about it all the time, should have put it on spacebar or anykey =\
"forbidden move by pressing V" - oh no, I did not have time to implement melee attack but forgot to remove the binding :(