To start off; this is a really fun game. I love the smoke trail mechanic being both the damage and health of the character while being able to improve both stats. The rewards system of receiving upgrades for defeating an enemy feels good (especially against the aim assist fireball). The smoke animation that floats above the fire that is placed around the map is really nice and the characters are really fitting to the theme. The music is fantastic and the UI looks great while being easy to navigate. All-in-all a great User Experience. There are some minor bugs where the graphics setting does not change, there are multiple of the same resolution option in the Settings menu and when opening the Esc menu and pressing E for the upgrade menu an overlay of the upgrade menu is seen overlapping the Esc menu. The walls do not fade away enough to reveal your character from some angles and this makes it hard to manoeuvre and dodge the aim assist fireballs (the aim assist is not a bad mechanic, but it felt good when I finally figured out how to inflict my revenge). The game can be soft locked by entering the Esc menu, selecting Main Menu, Settings, changing the graphics and then starting the game. Repeating the above steps once and then when you start the game the second time and press Esc the Main menu button no longer works. You will be able to Resume the game but now when you die the Respawn option no longer works either and the only way to continue is to close the game and re-open it. Other than that, any minor UI glitches can be reset by dying and the only bugs found during gameplay was being able to stand on an invisible platform after falling off the path, however the character is not able to get back on the path and has to fall to their death to do anything other than run infinitely into a wall 9at least the fireball cannot get me here ;)
Other than sprucing up the level design, the only addition I would make is to add an indicator for dealing and taking damage (either visual or audio) to just help with surviving longer. Maybe even make the sections of the smoke trail more distinct as a "healthbar" of sorts. This will make dying to a fireball more insulting when the wizard decides it is my time to go.
Overall, this was a great time running around and discovering the game. I just hope there is lore added to the game at some point because I'd love to know why my backside is leaving a trail of smoke as I run through Hell.