If your shield breaks when you die, it doesn't display 'Broke!' like it normally does. This has caused me to go 'huh why did I die' a couple of times now.
On a similar note, if you die on the fourth card of a room it draws the next room. I guess that isn't a bug per se but it seems more sensible to stop the game before the draw - both since that's how you'd play the game in real life and otherwise it looks like the game is continuing.
The card called Empresss should probably have one less 's'.
The potion rule could be worded better. I didn't realise that wasting a potion still counted as using a potion, and used three potions in a row assuming that I would get the healing from #1 and #3.
This is less a bug and more a design thought, but I think the game could visually communicate the 'state of play' better. Yes, one can work out whether attacking an enemy will break your shield or kill you, or using a potion will make you waste it, but if there was some visual cue by/on the card (e.g. it was tinted slightly?) that would make it a lot clearer. Part of the appeal of Donsol's design is the minimality and it would be a shame to lose that, but I still think it's possible to retain that and communicate more visually.
If the streak system as described above is implemented (which I am completely in favour of!) then the health meter should read current/max so you don't forget what your max health is!
p.s. I found this game thanks to the RPS article, watched the tutorial vid and thought 'this looks like my sorta thing', so I bought it and have been enjoying in greatly since. Many thanks for making Donsol!