Boy was this thing's launch underwhelming and disappointing. I played with friends and it was a pretty middling experience, but with randoms this would be a fucking nightmare.
I understand the devs not wanting every aspect being treated as though its coming from a sequel to Deep Rock Galactic, but if they didn't want that comparison maybe they shouldn't have called it motherfucking
DEEP ROCK GALACTIC: ROGUE CORE, a name that makes it sound like either an expansion or a sequel. It also doesn't help that over half of all of its assets are reused from Deep Rock Galactic either, including voice barks, the zones, the weapons, the deployables, the grenades, and more.
I have a few general categories of grievances I will go over, but if you take one thing away from this post it should be this: Do not buy this game in its current state unless it is at a discount of 50% or
more.
1) Issues of Completeness
Now, this is an early access game, but it is also an early access game built over 3 years on an existing fully featured engine from its predecessor, using most of its predecessor's assets, and many of the mechanics completely unaltered. It has 1 enemy faction, 3 bosses (of which one is very buggy), 2 game modes (Standard and Gauntlet), and a very large yet very empty mission hub.
The enemy faction is just "glyphids if they were annoying monkeys" complete with their own version of "guy who hides in the back and plinks you with projectiles" and "big tank with a beam attack that leaves him vulnerable". They duck, weave, jump, and in general move in a way that is janky to track and shoot, their profile is awkward and indistinct, and you feel like 9 times of 10 that you miss there simply wasn't much you could have done to hit them. They lack the tight audio design of glyphids who would roar and hiss as they moved and had very distinct easy to pick out sounds for almost every special unit that would warn you when they were in the area or beginning to attack which the space apes seem to have very little of (or perhaps it is drowned out by the constant yapping of your boss robot in critical situations, or just poorly EQ'd). This leads to very frustrating situations where you will suddenly find yourself surrounded by them and taking damage to your important and difficult to replace armor without there having been much of a way for you as an individual player to react to that. In general they just feel under-cooked, an issue exacerbated by their lack of varied unit types. If we were going to reuse every other asset from Deep Rock Galactic why not also port in the reliable and tooled up glyphids as well to add some variety, and just tweak their AI a little to match the higher aggression level the game seems to be aiming for? Slap a green glow on them to let us know that they are extra evil now or something. The way they went with this is just baffling to me.
The game is played in two modes, standard and gauntlet. In Standard you go through a cave system (which invariably generates as a straight line of linear caves directly to the exit elevator with the way forward marked by a big glowing cable) on a ~11 minute timer, mining a mineral called expenite for upgrades and killing space monkeys. Occasional side objectives pop up that you can tackle if you have time to deal with them, but there are only maybe a a little under a dozen of these and you will have seen them all by your 5th or 6th run. Occasionally there will be a side path you can very briefly explore to find an extra mini-game or, as is more often the case, a dead end with absolutely fucking nothing in it. After you clear a couple of these nearly identical caves there will be a brief boss battle against one of three bosses, then your robot manager will take the credit for your work and the game will fade to black before spawning you back in the hub. The other game mode is called gauntlet, it is completely identical but the maps are a little longer and you have a quota of space monkeys to kill before the timer runs out... that's it. OG Deep Rock Galactic has at current count 10 game modes, each of which is highly distinct and it costs exactly the same amount as this game.
Then we have the Hub. In the OG Deep Rock Galactic the hub world was the space-rig, a lived in industrialized work camp that was came across as both advanced and economical. Complete with a bar right next to the deployment screen for everyone to grab a drink before piling into the drop pod to go down and kill space bugs like only dwarves can. In Rogue Core we have the Ram-Rod, a ship that looks like it was designed by pansy space-elves covered in sleek heartless grey and both vast and completely empty of little mini-games to play and toys to fiddle with while you wait for your team to get back from grabbing a snack between rounds. It has a bar, but gone are the days of gathering the lads together for a quick round of pints because you are managed by a pompous robot who demands you play tedious time consuming mini-games to justify earning a pint complete with a display board next to mini-games informing you, a dwarf commando, about the health downsides of having an ale. Once you're done dancing like a good little boy or girl for this heartless machine, it will play one of several bugged out pint pouring animations and you can have your underwhelming space beer with no notable mechanical effects (in the first game, certain beers gave you buffs on the mission to come). Don't you dare think you can grind out a couple of minigames while your mates are away between rounds either, because any progress you make that you don't spend vanishes between rounds.
2) Issues with Mechanics
I have four major hangups with the way this game plays, divorced from its incomplete and unsatisfying content, and I think you'll see these repeated a lot in other negative reviews. We have the threat timer a ticking clock which limits how long you can stay on a stage, the negotiations system of acquiring upgrades were you enter into a "negotiation" with other players for who gets what in a limited pool of perks each time you upgrade, the game's obsession with readying up where doing almost anything requires all four players in a lobby to be standing still in one place all grouped together, and the lack of real loadouts.
The threat timer is a good idea with bad implementation, the idea is to force players forward, keep tensions high, and make them balance decisions on which bonus objectives they do and which ones they leave on the table because once the timer runs out invincible worm enemies will spawn and promptly wipe your team. The issue is that it isn't prompting any kind of decision making at all as once you figure out how it works you go down the path of the very linear level doing every side objective you come across until the time hits a few ticks past 3 quarters full then the whole team books it to the elevator ignoring anything they haven't done yet so you can escape before the worms arrive. You never weigh the "risk" of staying past the timer, because the "risk" is that you lose the run more or less immediately. In my opinion there is an easy fix to this, which is switching the timer from running per-stage to run-wide, and every time it ticks over the number or strength of enemies should increase Risk-of-Rain style. Now you are actually considering if it is worth staying for extra optional objectives and facing stronger foes going forward for the rest of the run or if it makes more sense to just dip out now for a more resource dense stage later. As is there is no engaging decision to be made, the timer is basically a bus schedule, you check the time and you either leave for the next stage or miss the bus and get wiped.
Next is the negotiations, every time you earn an upgrade in a run the whole party enters "negotiations" where a limited pool of perks appear and players take turns claiming the ones they want, theoretically bargaining with each other over who gets what. The issue is that in a party of four people who are co-operating the same thing happens every time, the perks that show up are just good enough to get 1 or 2 builds online out of four players and the other players are left with a grab bag of useless scraps having sacrificed everything fun or interesting order to make sure the team has enough functional builds to actually win a run. So every successful run is just two shmucks in cuck chairs offering all the good perks to whoever had a build solidify the fastest. God forbid you have uncooperative players who will just eat perks at will, because then NOBODY has a good build and the entire run is guaranteed to devolve into bitter bickering and failure where the only thing at fault is that everyone involved wanted to have fun this run but the game doesn't support it. The devs seem weirdly married to this mechanic as well which makes me fear it is here to stay. The only path forward here is to scrap this idea entirely and just offer each player their own personal pool of perks so we can all create fun builds guilt free with the option to coordinate niches amongst each other rather than against each other.
The readying up mechanic is another easy to fix pain point. To start a mission you wait until your whole party readies up by getting into the drop pod, then you arrive at the mission and walk up to a wall where the party assembles two drones then stands in a circle behind them to ready up to start the run, then you walk into an abandoned camp and all gather up stand in a circle to ready up to get your primary gun, then you all stand in a circle to ready up to pick up your grenade, then you finally enter the stage, and every time you deposit enough minerals to get an upgrade you need to get everyone to stand in a circle around the upgrade bot to signal they are readied up to get a perk. This pointless time wasting gets very old very fast. This game needs one ready up screen that drops you directly into a mission then whenever someone opens a container or unlocks an upgrade that requires everyone to "negotiate" a choice of weapon or perk just pause the game (as it does during negotiations anyway) and offer it to every player regardless of where they are in the map. Yes maybe this is
ludonarratively dissonant 
because your dwarf is too far from a guns locker to realistically have picked one up or whatever but frankly I'd rather deal with that extremely minor break in immersion than have to herd cats all day for every ready up screen. Please stop wasting my time and let me play the game.
Finally we have the lack of real loadouts, this probably bothers me more than other people but for the life of me I don't know why we can't just choose what gun, mobility tool, and grenade we start with. Instead we have to play the ready up game every time we start a mission and then negotiate for which 2 players get guns that are good to use and who gets stuck with the lightning gun that is completely useless and the machine-pistol that can't hit anything. Choose a few solid simple weapons and tools to make default options you can just start with and then have everything else be in-map loot that outshines these basic starter options. This is basically how it works already once you run across gun benches and heavy weapons crates (where you'll immediately abandon your junk gun for one that actually feels okay to use) so why add this friction of not starting with a gun you feel is useful?
3) Issues of Taste
These issues are matters of personal aesthetic taste or polish issues that your mileage will vary on, but they piss me off anyway so I'm going to talk about them.
First up, the new mission control, what the fuck happened to my tired exasperated mission control from the first game? The guy who was just a perfect blend of tired, sassy, and grateful. Now I have this stupid robot with a speech impediment who constantly talks down to me and then takes credit for all my work at the end of each mission while refusing to serve me a fucking beer. Why the fuck am I listening to this thing? Am I the super skilled dwarven commando called in to deal with a problem so grave that even the other already super badass dwarves can't or am I fucking 7-11 employee who can't be trusted to tie my shoes and can't afford to lose my job. Are you telling me that I, apparently the best of the fucking best of all dwarven warriors don't demand enough respect to be able to order a fucking pint of ale whenever I want one? And when I do order one I have to go do a workout in front of a security camera to prove I'm working off the weight gain and then the robot sasses me for drinking anyway? What am I not "working out" enough fighting a horde of giant interdimensional space monkeys in the pits of tartarus? What fantasy exactly am I living here? It feels like I'm one step from reading a lore entry where I find out that this robot is my wife's boyfriend.
Okay well, I guess I don't get any respect on this ship but hey maybe we're just contractors or something. We are still told we're super badass commandos, I mean hell here's a guy called SLICER with an exotic energy sword and an airdash! Surely this guy has the best of the best equipment? No, this guy doesn't even have a fucking gun. He has to scavenge one from the ruins of a mine, and there's a about a 1/2 chance the gun he picks up sucks. He also doesn't have a shield generator like the regular dwarves do, instead he has "armor" a non-recharging extra health bar that doesn't even fully block damage to my actual health bar and is constantly being depleted by stray hits from teammates. My guys outfit has a billion techno greebles all over it and apparently collectively they make me about 1/3rd the dwarf I was when I was a nameless generic miner in the first game. My cool sword has an awkward input to use and a long cooldown and is best used while surrounded in a blind panic, my air dash in anemic, and I have an anti-projectile forcefield I can put out every once in awhile which is about a third as effective as the one the gunner classs could use in the first game. If these guys billed themselves as elite commandos then they were doing so to rip off DRG, I'm not even sure these guys have ever seen combat before. None of these new characters are half as cool as they want you to think they are.
Our "cool" reclaimer star ship is indeed very big, its also very grey and very empty. I found myself wishing several times that I could take a shuttle to the space rig and hang out with the real dwarves and have fun at their place instead. Also why does every dwarf commando have a new high poly face and shitty hairstyle that evokes the overweight barista at a starbucks you know is spitting in your cup rather than a grizzled veteran operator? The driller from the first game would be giving every single one of these greenbeards swirlies if he was around.
4) TL;DR
This game has muddled mechanics full of friction, anemic content offerings, weak direction, and a long long way to go. Don't buy it for anything more than 20 bucks Canuck, and even that is pushing it. Even divorced from the Deep Rock legacy its just not a particularly good rogue-like. Give it a year to cook then check in again to see if it is going in the right direction.