So far, my impressions of this game are pretty good.
Good itemization with potential for end-game grind/achievement
Diverse skill-tree with flexibility to pick skills from multiple sub-categories
Has small puzzles/mini-games to break up levels
Has a specific art-style that may appeal to some
Allows for some clothing customization, potential for more
Lots of inventory space. Lots, it's great (and you get a stash, but not a shared stash)
Has a sense of humour
Party play! Works well, even with latency, group buffs for everyone!
Pets, have your own follower, each with their own unique abilitiy to complement you
Skill reset is possible! It's got a price-tag, but if you think you screwed up you can undo it
Haven't encountered many bugs (2 to be exact), so it's good to see them being patched/fixed
Re-playability may be an issue for some, it has a game+ sort of mode, but only the same 4 dungeons (which are big)
May be confusing to begin for people not familiar with RPG/Dungeon Crawl gameplay
Difficulty scaling may need work, at this point I can't vouch for higher difficulties
Game black-screens when you close the window, this persists through windowed and fullscreen mode (game runs in the background, but you can't see to click or rectifiy)
Newer players may struggle to understand the scaling resource cost, it isn't properly reflected in skill cost descriptions
Pets are currently lack-luster in terms of damage/functionality
Skill bar slots are quite limited, it's not possible to cycle to a second skill bar or use F-keys etc.
It comes across as a voxel-based game with similarities to games like Torchlight, with references to quite a few things (the more obvious ones being things like Zelda, which was cool and somewhat nostalgic).
I personally found it very easy to pick up and learn, with most things being quite intuitive and any issues I had, I could check the in-game help/guide. That said, I had to explain a few concepts to people I got to play, the big one being socketing (the only confusion I had was seeing the rarity and mixing it up with the socket colour), I'm not entirely sure how this could be streamlined, perhaps a small image in the guide with arrows.
Itemization seems good, as of posting this I've only cleared normal and started intermediate on one character (plus a few others close to clearing normal), I've found that it has potential to go quite far, with the inevitable grind for the perfect socket combinations, unique drop of the item you want, etc. This is of course fine, assuming that the challenge remains present. In my current iteration, I've found that with enough gear refines and appropriate sockets, even without building defensively at all, there's no threat from monsters or traps. This of course may change in higher difficulties, but there should still be some kind of progression.
In terms of progression, I found the first dungeon and a half scales pretty linearly, then there was a gear spike where sockets and refines became more viable, new skills unlocked and suddenly what was a pain to deal with (healing wolf packs with resistance) became easy, this is completely okay, as long as there comes another stage of difficulty.
Anyway, going on, skill selections are good, being able to cross-class your trees is great. Want to be a rogue with some magical prowess? No problems. Want to be a barbarian with sentry guns for backup? You can do that! I think that's a good thing, it allows build diversity. Could lead to further itemization with +skill level on a rune or added flavour on weapons/armour. I found it slightly perplexing being able to progress down one side of the tree, but then unable to come from the final skill back to the top layer (in order to skil a skill I don't want), you can only go up the tree, I guess.
Resource costs for skills might seem steep at first, but this becomes more logical (and requires further investment into gear) at higher levels. Currently there's quite a few weapon choices, although more would always be welcome. Certain base items won't start dropping until specific stages of the game. By the end of the first playthrough, you should have seen most/all of them.
I like that there's higher difficulties, where you can keep your character, but I feel the endless dungeon mode (rng maps, map mods, possibly with influence) which I think I saw mentioned somewhere would be a good improvement for later gameplay, especially if new areas could be introduced (or new monsters).
Party difficulty scaling is great, while not everyone will welcome it, it stops the game feeling too easy with group-orientated skills. Did I mention there's a support sub-class? Group-buffs? No? Well I should have!
Specific skills may be over-tuned, while it's great having that really high cost ultimate ability that deals loaaads of damage at max rank, it's not so great if it one-shots the boss.
Pets. Cool feature, feels lack-luster. There's room here for much more. More pets, more utility for them, longer durations? Give them an auto-attack or make them collect gold. In their current iteration they deal pitiful amounts of damage. This may be due to a level discrepancy (i.e. pet lv.25 vs monster lv.31) but I found that they weren't useful. By making the cooldown more powerful, people might be incentivised to build around pets. Potential to have all pets summoned at once? (could lead to screen clutter, especially in group-play) would make using pet-runes viable.
Skill bar is somewhat limiited, which forces you to choose your skills carefully (that's good), but having pets also require a skill bar slot, to properly use, so do consumables. Health potions are pointless, almost, the only reason I found to use them was if I had no other means of healing early-game (or I face-tanked traps later on). I feel a second skill bar would be greatly beneficial, it would allow for more diversity with skills, quality of life with pets/potions/town scroll, etc.
A skill-reset is possible, that's great, unfortunately it might also make new characters somewhat obselete. The only real difference in making a new character is the starting gear and which of the 3 base classes you use as a start-point. The rest is purely cosmetic (which you can override) or can be changed in a few skill-points.
Lastly, mobility skills. There's only one. Leap. Mobility skills are sort of a quality-of-life thing, not having to run 200 steps in the wrong direction to get back to that one item is a nice QoL, admittedly that could be seen as reducing the life-span of the game, but there's still that same element of back-tracking and exploration without that. One mobility-orientated skill (Dash doesn't count) would be nice for each class (not all, rather 1 per base/sub-class in total, i.e. mage gets a short-range teleport, rogue gets a vanish trick).
Anyway, I'm sure there's stuff I missed, but that's my (fairly detailed) impression. I like this game and I'd recommend it, I've given copies to a couple of my friends and it's pretty fun to play in groups. I hope to see more challenge/replayability in the future. I'd probably give it a 7.5/10. That's comparing games in it's genre from established publishers with a lot more financial backing. It's a bit more niche than Diablo or something like that, but it's a good game, it's got potential to be pushed into something that can be played for hundreds of hours, it's just not quite there yet. Is it worth the price-tag? Maybe not for everyone, but if you've played (and enjoyed, hopefully) the likes of games like Torchlight, or just like the genre, give it a go.