Great game and premise, the mechanics are fun and gameplay feels smooth. However, I have a bit of feedback about the burn effect, because it simply sucks.
At first, it seems nice to have a status effect which can cause a lot more damage than your starter weapons can.
However, as there is no late-game scaling, an effect that has no guarantee to give you even a measly 3 damage per stack just ruins your build later on. considering the fact I cannot sell artefacts once bought or gained, I might gain a coal from a chest that will simply ruin my run with severe damage reduction.
Because I felt like this is a whiny complaint, I also have thought of a solution for it - area scaling. If the burn damage could start off small, but scale per area of the game you have passed, you might then be able to incorporate it to your build without it taking away from your damage potential. You don't have to use my solution, but I'd like another solution then, because I think burn is a great gameplay mechanic, and it's sad for me to avoid it because of it's scaling.
If I'll have any more feedback, I'll post another comment. Other than this, the game is great!