Oh boy, that game is really good with time pressure!! I definitely think that the time pressure is essential to the game - but I also feel like it might be helpful for new players to slow down the first two fights at the beginning a little, giving the player more time to get into how this game is played!
I can see a really fun gameplay loop in this game, especially with more polish! :) It immediately reminded me of Inscryption, one of my favourite games. I also liked the little map that the game generates and that the player can reroll - It has a very good board game aesthetic!
If I am perfectly honest, even after a few fights, I still don't know where I can see my energy-meter and how much energy I have left :x
All I gathered is that there is a set amount of energy each turn that I can spend, but that's about it. I feel like especially under time pressure it's really hard to parse what is going on exactly. (But that might also only be an issue for me!)
Otherwise, all my other points of critique have already been said in the other comments! Especially turning card rewards down after winning a battle - or maybe even selling particular cards from your deck - would be great!