Blightbound

Can't recommend this until they allow offline play with AI. It's obviously functional in the game as it's part of the tutorial. Not a high enough population to find games so it's essentially unplayable.
EDIT: Devs added bots! The game is much more accessible now. Thanks for listening to your customers :)

Not very far in, but I'm genuinely confused as to what the hate is about. Seeing lots of complaints about not having a single-player mode, which is false (though the "Play With Bots" button is maybe a *little* difficult to see, and the opening menu options of "Play Online" and nothing else should maybe be reconsidered from a user experience perspective). I can charitably interpret that as wanting a mode where you don't have to collaborate with the bots' questionable AI, and if that is what you want, then I guess this probably isn't the game for you: The role-asymmetry is baked pretty deeply into the design, and it doesn't seem likely that such a mode was actually being built for. At the end of the day, this is a game with multiplayer dynamics, so pick one: A) play with friends, B) play with randos (and deal with slow matchmaking), or C) play with bots (which act like friends but are kinda dumb).
Beyond that, the inter-mission RPG mechanics seem fairly compelling, the art and visuals are well done, and though I see lots of hate about bugs here, I have literally encountered zero of them. Maybe they've been hotfixed, maybe I'm just lucky, grains of salt, etc.
I'll update if I am shocked by some negative revelation, but right now I'm liking this game quite a bit.

Game desperatedly needs AI companions(even if only when disconnection occur), when someone disconnects you get stuck into loading for a long time and then the mission automatically fails, your hero get f*up, this is ridiculous. Other than that I'm loving the game . For the people complaining about not being able to choose your role, just play a little longer cause that option will soon be unlocked (prosperity 9).

Best enjoyed with 2 friends in local coop imo. Online Matchmaking is a bit slow. The gameplay is a Castle Crashers/Dota/Diablo Hybrid with almost "Darkest Dungeon level" graphical fidelity.
On higher difficulties you really need to play your role right, on lower difficulties its almost a (easy) brawler.
You can modify the way a hero operates with tons of items and skill combinations. If you are not scared away by the significant amount of grind that will be necessary for higher difficulties i recommend this game.
For Solo-Players i wanna add: Solo with 2 bots is doable up to a point, higher difficulties (more than 10 lvls difference) will be almost impossible.

A good game for playing co-op (as hotseat). The only one big flaw I really don't get is that you barely can play solo: bots are too stupid and, although I love playing as caster heroes, sometimes I want to play a different hero, but it's simply inappropriate to give bots a healer role

Dont let the negative reviews scare you away from this one! It might not seem like it at first but this game has pedigree. Its another diamond in the rough from Devolver. IMO its one of the more accessible indies they've picked up in the last several years of back to back bangers. Ronimo has a small list of titles, but Awesomenauts released in the glorious age of xbox live arcade and has continued to get updates to this day. In an age of $60 AAA Flops and heartless money grabs, Blightbound stands true to its roots. $20 is a bargain.
The (now fewer) negative reviews i read had me holding off on purchasing Blightbound for a couple reasons. Complaints of the grind and difficulty curve, poor bot ai, connection issues, repetitive levels etc. You'll run into them here as well. Im here to denounce them all fools.
The difficulty is a non issue, if you're paying attention to the difficulty ratings of the missions and matching them to your party level in an easy to understand UI. Eventually you will be able to handle mission difficulties several levels above your party level if you take the time to master the gameplay.
That brings us to the curve and the grind. If you dont want to NO PROBLEM. Im 10 hours in with a single friend to co-op and we have switched characters so many times we are still running Blight level 6 or less (Normal or Easy). We TEND to find Easy mode a cakewalk, but still sometimes get pasted by a new boss, which is great! Its great because even if you die you retain all your material rewards, which filter into crafting for better gear. This is a roguelite. If your problem is dieing, you're playing the wrong game.
10 hours into the game Im still unlocking new characters who all have individual stories and questlines to follow. I havent finished a single one. You will find yourself repeating the same levels often, but with new characters and new storylines (albeit sparse ones) to continually unlock you will find yourself jonesing to return. There are still a handful of levels we havent explored or cleared entirely, and enemy and trap mechanics seems to change as difficulty increases, leaving the missions feeling fresh.
Ill say initially progression can feel a LITTLE slow. But reliably whenever i began to feel that way, a new feature for my refuge, or another character would drop into my lap expanding and deepening the gameplay further. At this point i am so earnestly impressed that i feel compelled into writing an over the top review.
The Bot AI is the one thing that actually needs some love. Occasionally they will entirely misbehave, failing to trigger puzzles, or triggering where they ought naught. I imagine this makes for obnoxious do overs in single player. However, in multiplayer the bots are always leashed to one of the players, and in practice if the Bot is getting uppity one of us just walks to the other side of the room while the other solves the puzzle.
Let me tell you that my PC is inches from death, and a recent windows update left my disk drive hanging like a mother-♥♥♥♥♥♥, causing most games to crash. Blightbound seems to have a ton of built in saftey measures for when your pc or network hangs up. Coop partner reports that I am invincible at all times that my game is frozen. In the few instances i jumped the gun and restarted the game or my pc before Blightbound unstuck and continued to run, all my items and quest progress was saved as i was returned to the refuge. I was earnestly awestruck. Thats the good ♥♥♥♥ right there. No game/server connection issues whatsoever. Your mileage may vary.
Best enjoyed with a Controller for Melee and a Mouse for Caster and Menu navigation.

Game is great but I did not have friends to play with and I did not enjoy the matchmaking system, would maybe have preferred to play solo and then play with friends when I wanted to.
I'd recommend ONLY if you have 2 friends to play with.