This is an extremely solid pre-alpha. While I think the artwork is basic, the consistency of the style across the game helps it hold up and gives it the charm of something like an early newgrounds game. That said, the style's simplicity can cause some ambiguity about what is a wall and what is a walkable floor area, since both can share the same overall simplistic aesthetic. I do think the animations are solid and weighty, however, which lends itself positively to the overall feel of the game.
The Diablo/Zelda inspirations of mana bars and block puzzles mix well, though in this pre-alpha stage neither element feels especially in-depth, though that is likely just due to it being a pre-alpha and a tutorial dungeon. Currently, much of the combat revolves around kiting the enemies into formations that would be best exploitable with spells, which generally functions well but can be somewhat tiresome when overwhelmed and needing to repeatedly move them into exploitable formations or run around for extended periods shooting fireballs at them. The feel of the combat is solid, but it could benefit from further stipulations (i.e. some enemies being more powerful but also explosive, thereby encouraging a focus on them first to yield explosive damage) or incorporating a secondary type of depth to other actions (perhaps successful dodges yielding a minor refill of the mana bar). Also, I think the dodge roll could use a smoother outro or less ending lag. I believe the reason the lag is so long is to prevent exploiting it, but the lag can feel so long that simply running around attacks can seem more favorable. The amount of time it takes to break debris could also use some reducing as there's a lot to break and a full set of swings being needed to break them can eat into the playtime.
Otherwise, I think the fire mechanic is a solid base to build the combat and puzzle solving around. Currently, the puzzles seem to trend simplistically toward finding the ignitable object and then shooting/hitting it, but I feel that with additional combat elements, moving elements like conveyor belts, and secondary properties being added to the fire like light/shadow and/or heat properties being used for actions like cooking, creating heat plumes for ascending, or controlling temperature-controlled switches would help imbue further depth into the systems.
Overall, solid work! It noticeably needs more elements and tweaking, but it functions well as a pre-alpha and lays out the positive qualities of the future release quite well!