While I want to be kind to this game for being as fun as it was during early access, a lot has changed with the release of the game. Not a lot of it positive in my eyes.
1) Many of the fun ways to play the weapons has been altered or made much harder to achieve. The hammer dodge jump? Removed for being too much fun. Now the hammer is incredibly clunky and confusing as to why it even exists. Ah, yes, I would like to play the SLOW MOVING, CHARGING WEAPON CLASS in a game where life or death comes down to less than a tenth of a second. Do you play your own game or is there a joke I'm missing somewhere? How many armor items do you need to acquire to make completely immobile, attacking-once-every-two-second gameplay viable? Likewise, the blender sword build has been removed and replace with a single spin slash. But now it has fire. Exciting to the three players left who actually use the fire status, I'm sure.
2) The majority of the relics are bafflingly bad."Hmm, would I rather heal every single time I cast a spell for 2, or heal for 1 every time I finish a room? Gee, game, this is a hard choice. Why not invalidate both options and just gain 5 armor on every spell cast? Which is health, but better?" Sure, healing items have synergies that can work together to make an undying monster, but I want ANYONE to find a justification for an item that heals a SINGLE health point upon ENTERING a new room. Go ahead. An entire relic slot that takes 5 rooms to be as useful as an apple. It's funny, to say the least.
3) The final world is horribly designed. I have no other way to describe it. The boss mechanic being horribly telegraphed lasers that do 20 damage less than 0.2 seconds after a telegraph, in a room full on enemies that can and will do 45+ damage per hit, and then having that laser be spammed 10 times just to make sure it hits the player at least once? Yeah. Good job. The massive orbs aren't much better, doing 27 damage and taking up an unreasonable amount of the screen space. If it was the ONLY thing I had to worry about? Sure. No problem. BUT AGAIN, the 6th's world's scaling makes it impossible to avoid everything.
4) Healing is now required, and is no longer a suggestion. I used to run through the whole game without any healing relics, as a fun challenge for myself. Now? Good luck. Bosses have been given extra attacks that fill the screen with clutter so that at least SOMETHING will hit you, enemies are more aggressive, and safer playstyles have been nerfed or limited. Every single build I make now has to have, at minimum, a way to heal 30 health on demand, because that is how much the most basic enemy does in worlds 5 and 6. Before ANY modifiers to make that worse. That means every single build has to be a crit build or an armor build unless you play flawlessly. So every build needs at least 2 crit heal gloves, 2 juicy opals... and while we're at it, we might as well weaponize the healing, so... let's grab a scythe. Now that we have sustain AND healing, we might as well get some armor, to weaken any hits we take while healing. So armor boots or perfect cast armor wand. 2 of each would be ideal. Damn, no more room for damage artifacts? Oh well. At least I can survive a few hits from the enemies now. Didn't get any damage or crit crystals, though? Just end the run. It's done. After all, surviving the enemies doesn't matter if you can't kill them. For those that don't believe me? Try a run with the bow and spreadshot. Get crit heal gloves. Get a juicy opal. Get heal berries. And watch as you heal over 30 health every second. Congratulations, you have unlocked video game reviewer mode and the only build that can facetank any amount of damage in world 6.
5) New boss changes are not enjoyable. Early bosses have been given massive increases to either their HP, damage, or new mechanics that can and will clip you. Boss variants are just straight up unreasonable to deal with and seem to have lost the understanding of what made the miniboss variants fun. The boss variants don't add a new gameplay twist, they simply remove the weaknesses they had and give them a huge set of new attacks that are both unenjoyable to deal with and epitomize the problem with modern gaming: Why make a fun encounter when I can just make my boss invulnerable and swarm them with summons that do nothing to the boss's health bar? Everyone loves when the boss just inexplicably becomes invulnerable and chooses when you can hit them. We used it a little before, but NOW we can put it on ALL OF THEM. However, nothing epitomizes this problem like world 2's boss variant: Between each phase shift, he teleports to his throne. On normal, this lasts about 10 seconds. You can rush him and take advantage of blind spots to give yourself free damage time when it ends and he emotes. On altered? He stays invulnerable for as long as it takes you to defeat 20 summons. That's right, a reasonable TWENTY enemies. While being attacked every single second by the boss. It is so bad it makes me angry.
If Brugal is the poster child, Poltergeist might be the worst boss I have ever played in any video game. I beat it first try with my wife, and neither of us lost a life, but we were both so annoyed by it that we put our controllers down and went off to do something else. The entire fight is nothing but a series of rotating summons that do almost nothing to you. You just have your time on this earth taxed into nothingness. Did you not kill the summons FAST ENOUGH? Good news! The boss can immediately re-enter the invulnerability and summon the EXACT SAME SUMMONS as soon as it ends. It is a literal run killer if you got unlucky with damage pick ups. (Who designs garbage like this and is proud of it?)
If by some miracle the game developer reads this? Here's your TL;DR : Stop adding invulnerability phases to your boss fights. If you're going to have summons, they need to share a health pool with the boss. NOTHING, and I mean NOTHING, is more frustrating than being given a meaningless chore in the middle of an otherwise entertaining encounter. Bosses deciding it isn't your turn to hit them has never been engaging in any video game. It never will be. You remove any and all nuance to a fight by doing this. I can't choose to risk taking more damage and attacking when I know I shouldn't. I can't choose to do anything other than wait or do the homework given to me by the boss.