Very fun game! I've only played normal mode so far, so any and all feedback is relevant to normal mode only.
I also completely understand that most, if not all of my feedback is already known and you guys probably are working/planning to work on them :)
The visuals are very nice and remind me of Genshin Impact and Breath of the Wild (and obviously risk of rain 2). Performance was a bit meh, started out good, but quickly went under 60fps with lots of stutters (RTX 2070 and I7-6700k). Balancing was also not great on normal mode, I definitely felt powerful and a force the be reckoned with, but I also killed the final boss within 30 seconds. The chest spawns were a bit whacky, some even spawned on the geisers which made it quite difficult to open the chests.
The chests also felt overpowered, not only were they dirt cheap, the price didn't increase overtime and you get to choose your upgrades every time, made the chests feel more like a pure choice, rather then some good old RNG. Eventually you could buy all the chests on the map, and only have spent around 5-10% of your gold. Would have felt a lot better if the chests increased in price at least per new level you enter (maybe even scale it with the difficulty, rewarding players for clearing the levels fast)
Audio was also very nice, although sometimes I didn't hear an enemy spawn behind me, which wasn't anything bad, just felt like something was missing.
The abilities of your character also felt a bit unbalanced, It feels like all the cooldowns of the abilities should be somewhat higher, right now there is no reason NOT to spam your abilities.
tl;dr
The game is very promising, the visuals are good but need some tweaking in the performance department. Audio is great but also lacking in some points, and the game does a very good job a fulfilling the players power-fantasy! You guys got a great game right here, keep on going!