I liked the game overall and if the development progresses at this quality level, this game will surely deserve at least a 4-star rating (or Steam thumbs-up).
Regarding constructive critic:
My personal playstyle is very agility/luck based. So far I played 2/1/2/4/4 and 2/2/1/4/4 so far. Currently it feels like the game is not supposed to be played like that?
I have trouble identifying when to progress into the next zone and the punishment for doing so too early, or having a build around luck where random loss is part of the build, is very harsh. With just a dozen or so allowed fights (unless slightly modified by equipment), every loss in a playthrough hurts very much, especially when the level-up curve is so extreme (which I generally approve of!).
I would accept this as part of my playstyle if I had not felt like hitting a progression cap. Persistent equipment is migrating the problems, but I seemed to have capped the buyable equipment quite far and to unlock other slots I would need to replay the game in other style I enjoy less. Maybe do not cap the equipment slots behind that criteria?
For the equipment, some random-stat dynamic equipment may help lessen that issue (Diablo-Style)?
As of now, I would probably rate it 3-Stars (subjectively due to my playstyle), but as it is "just an alpha", it does not deserve this as a public rating.