I enjoyed it!
I think I struggled a bit partly out of a misunderstanding about what kind of game it was due to other TF games I've played in the past. I don't know why I thought acquiring the items was a purely "for fun" bonus collectible that effectively let you see a fun TF again but make you lose, almost like unlocking an ending in one game might let you revisit it in a gallery.
Once I understood that the dungeon was actually meant to be tackled in multiple different runs, and the fact I got the items actually opened up new paths for me, I feel like I really saw the potential for the game. Whether items are the only thing that you retain across runs or if it can be expanded to have more things potentially react or change, like levels that shift corridors, or npcs who move or behave differently, maybe a monster changes behavior based on what tf you were under when you die to them for example. (if none of that is possible for various reasons then disregard but I still like the idea of how the items work in that space) I think the idea that dying is not a flat reset, that some of your actions may have accomplished something even if you didn't clear the level, is something that should be leaned into. I think it could maybe be more clearly communicated, it worked fine enough, I did figure it out eventually but I just feel like maybe slightly different wording or graphics to the "you died" screen might be enough to get the point across. I should say it is my fault, the screen does make it clear we aren't resetting, but that we were resurrected, but still, I just feel like that might be something is a bit lost right now.
I'm very curious what role classes will play in the game. From what it felt like in the prototype stats don't seem to be a real factor and are more of a flavor thing. I figure classes could maybe alter text or descriptions for certain events or interactions while ultimately not really changing gameplay very much, but if you have a deeper mechanic in mind for them I'd be interested in seeing it.
I hope that feedback was helpful, I am looking forwards to whatever you decide to do.