- Selection Criteria
- #1 - Hollow Knight - Broken Vessel
- #2 - Lies of P - King of Puppets/Romeo
- #3 - Sea of Stars - The Catalyst
- #4 - Tunic - Garden Knight
- #5 - Ender Lilies - Knight Captain Julius
- #6 - Furi - The Burst
- #7 - Sifu - Yang
- #8 - Slay The Spire - Time Eater
- #9 - Hades - Asterius and TheseusÂ
- #10 - Cuphead - Dr. Kahl's Robot
- Honorable Mentions
- Challenge AcceptedÂ
I’ve said it once, and I’ll say it again. A good boss battle is a dying art in modern video gaming. Unless you’re playing a souls game, most boss battles will wash over you as you beat them to a pulp with little to no effort.
But if you’re willing to seek them out, there are still plenty of bosses more than willing to crush your spirits, and a lot of them can be found in your favorite indie games.
Down the years, I have shouted expletives and tossed projectiles at many indie game bosses, and I thought it would be fun to go through them and name some of the hardest ones I have ever encountered.
So without further delay, here is Indie Game Culture’s list of the Hardest Indie Game Bosses that Kicked My Ass!
Selection Criteria
To make sure we are picking absolutely brutal bosses and nothing but, here are the criteria we used to make this list:
- All bosses will be from indie games only
- All bosses listed will be present in the main game, so no DLC or Fan Made content, and no optional bosses
- All bosses will offer the hardest fight within their respective games
- Only one boss per game.
Okay, grab a sword, gun, or whatever is handiest. We have some bosses to kill!
#1 – Hollow Knight – Broken Vessel

Since we are only considering main game bosses for this list, all of Godhome’s brutalities aren’t considered. So, with that in mind, my choice for the hardest boss within Hollow Knight was Broken Vessel, the boss you’ll need to take down if you want to get the Monarch Wings.
Broken Vessel is a tricky fight, as they are very mobile, have some tough attack patterns to learn, and they also make use of little ghostly minions to add an extra layer of difficulty. And don’t get me started on his infection ball bullet-hell attack.
Along with the Mantis Lords and The Hollow Knight, I would say this is one of the hardest fights you’ll encounter on your way to beating Hollow Knight, so good luck taking down this boss!
#2 – Lies of P – King of Puppets/Romeo

For those of you who aren’t aware, Lies of P was insanely hard before its first major update was released. Based on that build of the game, I could have included just about any boss from Krat in this list. But of all those I faced, King of Puppets was easily the most challenging.
The first phase is tough but manageable as you take on this bulky machine, as his attacks hit hard, but are slow and telegraphed. However, when they enter their second phase and Romeo comes out to play, the fight becomes a test of fast reactions, tight movement, precise parrying, and dodging mastery.
I haven’t gone back to the game since the update, so this one could be a lot more manageable now, but when I took this one on, The King of Puppets kicked my ass time and time again, earning them a spot on this list.
#3 – Sea of Stars – The Catalyst

Sea of Stars isn’t really known for its difficulty, as it’s a very well-paced game where you’ll always have the resources needed to make it through most fights with ease. However, the game does have a few fights that buck this trend, and the one that caught me off guard the most was The Catalyst.
This fight sees you battle through a room that is being protected by a Robot, and your job is to pierce their lines of defense and get to their control network. This is challenging enough, but when you get there, the real fight begins as you need to take them down for good to access the mainframe.
Because this boss has the ability to regularly heal itself, and deal huge damage, it’s super important you take out all of its turrets and systems fast, allowing you to focus on the core in the middle. Otherwise, you’ll be blown to kingdom come, trust me!
#4 – Tunic – Garden Knight

This may be a little controversial as, strictly speaking, there are much harder bosses that players will encounter throughout their time playing Tunic.
However, I want to argue Garden Knight’s case, as they are such a huge jump up in terms of difficulty compared to what you will have faced to this point, and because you don’t have all that much knowledge of the world and systems by this point, this makes Garden Knight an absolute mountain to climb.
The number of times that I have heard that players have fought them with no upgrades simply because they didn’t know it was an option is baffling, and even if you do know how to better equip yourself for this fight, Garden Knight will still serve as a real test of your ability to this point.
It’s basically the point in the game where Tunic cements the idea that it’s not a cute, cozy game. It’s an intense top-down combat experience, and if you aren’t prepared, this fight is a potential bloodbath. You have been warned.
#5 – Ender Lilies – Knight Captain Julius

Next up, we have Knight Captain Julius from Ender Lilies, a dark Metroidvania where harnessing the power of spirits is essential if you want to make it through this hostile world. However, even with heavily upgraded Spirits, Julius will still give you a run for your money.
Julius is kind of like Ender Lilies’ version of Elden Ring’s Crucible Knight, but in 2D form. The first few phases will lull you into a false sense of security but as the fight goes on, Julius will get faster, add brutal attacks to his arsenal, and will glow a fiery red as he comes at you hellbent on slicing and dicing you.
Beating Julius is all about learning his choreography, until it becomes a beautiful dance with a flurry of blades swishing overhead. He may not have had his father’s respect, but damn it, he has ours.
#6 – Furi – The Burst

If you’ve watched our outcry that we need more Boss Rush Games, then you know that Furi is one such game that offers bosses and nothing else.
I would go as far as to say that Furi doesn’t really have a weak link when it comes to bosses, and each offers a unique and cathartic experience, but if we’re speaking about difficulty alone, then we need to talk about The Burst.Â
The Burst is the Sniper Specialist of the ten Jailers you will face, and the one that offers the most well-rounded battle of all. To this point, you will have faced characters with strong melee, intense bullet hell sections, and weird gimmicks like time manipulation, but The Burst has it all.
Her bullet hell sections are intense, her ranged attacks are deadly, her melee attacks require pinpoint parries in quick succession, and she also has the gimmick of being able to cloak herself, making dodging, parrying, and keeping track of her whereabouts a real pain.
When it comes to Furi’s many mechanics, The Burst ensures if you have a weakness, she will exploit it. So plug those holes in your armor before taking them on!
#7 – Sifu – Yang

Speaking of bosses that serve as the ultimate test of all the mechanics you have learned in a game, Sifu’s Yang is absolutely this kind of boss.
Often, a final boss can be a bit of a letdown as they don’t live up to the anticipation the game has allowed for, but Yang lives up to the hype, acting as a true test of your Kung-Fu aptitude.
It’s a brilliant climax to the game that has you fight your own brother to end this quest for vengeance after the death of your father, and since he’s your own flesh and blood, you know going in that he will be more than a match for you.
Throughout the battle, it almost feels like he’s in your head and knows every move that you’re going to make before you make it, and only the most meticulous combos will cut through his defenses.
This battle is all about patience and the ability to take your opportunities when he makes a mistake or opens up for a counterattack.
The ending is bittersweet as you realize that vengeance isn’t as fulfilling as you thought it would be, but even still, beating this tough boss will give you that feeling of accomplishment all gamers crave.Â
#8 – Slay The Spire – Time Eater

If you watched our list of Indie Games that are a Nightmare to 100%, you’ll know that Slay the Spire is perhaps the worst of the bunch in this regard, as there are so many incredibly hard situations to overcome in this game.
However, of all these bosses you’ll face across the three acts of this game, the one that kicked our ass the most was Time Eater.Â
On the surface, Time Eater doesn’t seem that bad. Sure they have a huge health bar, but their attacks are reasonably low, especially by the time you reach them.
However, they have a unique ability that means that after you use 12 cards, your turn will end, and they will gain 2 Strength. This essentially means you need to be thinking ahead and managing your resources incredibly well, or you’ll find that you’ll be unable to defend yourself when the next turn rolls around.
The key to winning this one is making sure you end the fight as quickly as possible and try to be super-efficient by using as few cards per turn as possible, or alternatively, use more cards than usual to end your turn on your terms. It’s easier said than done, though, making Time Eater a very annoying Slay The Spire Boss.
#9 – Hades – Asterius and Theseus

If fights with bosses like Ornstein and Smough, or The Watcher Knights in Hollow Knight have taught me anything, it’s that having more than one boss to focus on is usually a massive pain in the ass, and this couldn’t be more true when fighting Asterius and Thesius in Hades. As it’s a fight that makes you which you had an extra set of eyes.
Asterius is an aggressive melee fighter who will relentlessly chase you around the arena, whereas Theseus will sit, likely offscreen and out of view, firing deadly projectiles to stagger you, and make Asterius’ job of crushing you all the easier.
The strategy here is to keep moving and take out The Minotaur first, but when you do, Theseus will burst into life with strong melee attacks, raining hellfire from above, and you’ll also need to find a way around his shield, as he will block all frontal attacks.
Many will argue that Hades, the final boss of this game, is the toughest of all, but in my eyes, this duo is easily the most frustrating and tough of all the bosses presented, and that’s why they earn a spot on this list.
#10 – Cuphead – Dr. Kahl’s Robot

Then lastly, on this list, we have Dr Kahl’s Robot from Cuphead. While we did consider giving King Dice this spot, we just thought that Dr Kahl pipped them in terms of difficulty, but let it be known, it was pretty close.
Dr Kahl’s Robot is a three-phase boss, and it’s rare that the first stage offers the toughest test in segmented fights like this, but with Kahl’s Robot, that’s absolutely the case.
This stage requires careful use of your abilities, it requires you to take out his Bomb Blimps as and when they pop up. Plus, you’ll need to avoid his death ray.Â
After that, you then have the Magnet and Nuts and Bolts combo, which is exceptionally annoying, and then the big crescendo is the diamond bullet hell section, which requires some precise movement to navigate as well.
It’s a very intense boss with a lot going on, but if you can beat this one, you can beat just about anything that Cuphead throws your way!
Honorable Mentions
Then, before we sign off, here are a few quick honorable mentions, which I’m sure many people are wondering why we haven’t mentioned, so here is their little moment in the limelight:
- Salt and Sanctuary – Witch of the Lake
- Terraria – Moon Lord
- Enter the Gungeon – Ammoconda
- Axiom Verge – Gir-Tab
- Sovel Knight – Polar Knight
Challenge Accepted
So there you have it, guys, the ten indie game bosses that absolutely kicked my ass. What do you think of this list? Do you agree with these picks? Did we miss any clear and obvious choices? Let us know in the comments and as always, thanks for reading Indie Game Culture.
- Best Beginner Hades 2 Keepsakes - May 13, 2024
- 15 Beginner Tips For Hades 2 Newbies - May 9, 2024
- What’s New In Hades 2? - May 8, 2024
I’ve had my fair share of disappointing pixelated experiences, but the bosses you mentioned really took the cake. The ‘Tumbleweed’ boss from Cursed Cave was especially brutal, I must’ve died like 10 times before finally figuring out its pattern. Great post, loved the laugh and the reminder that I’m not alone in my struggle