What's the full list of MIO bosses? In any good Metroidvania or Silksong competitor, you need some seriously challenging bosses to tackle. Luckily, MIO: Memories in Orbit has them in vast quantities.
With a whopping 19 MIO bosses, including two post-credits enemies, there's plenty to keep you busy in this platform game as you explore the huge MIO map. Naturally, some of them will put up a serious fight, so here's a little advice from us on how to get through each battle with relative ease. It's also worth noting that, to an extent, these bosses might not be completed in this order, but this is the order in which we found them.
MIO bosses list
- Egis
- Crow
- Flora
- Acat
- Calderon
- Atmos
- Nabuu
- Sawlong
- Anra and Dr Halyn
- Friends
- Lombre
- Vlad
- Ancile and Targa
- Debby
- Poltergates
- Sol and Vin
- Final Boss
- True Ending Boss
- Secret Ending Boss
1. Egis
Item unlock: Silo Access Badge
The first of the MIO bosses, Egis isn't too tough, but he might be challenging enough to take you out on the first try. In fact, the worst thing about these MIO bosses, Egis included, is that you don't always know they're coming. The first time we fought Egis, we unwittingly went in with just one layer of protective coating left before we'd even started.
Luckily, there is a Nacre Basin just above Egis' battlefield, behind an icy gate, so be sure to use it if you're low on health. Otherwise, it's just a case of getting used to Egis' moves and, for the most part, staying above him. The most difficult move to avoid is his rapid dart across the screen, but you can tell he's about to pull this move as he revs up, like a runner on their marks. When this happens, just stay put and prepare to jump almost as soon as the enemy reappears. Remember this, and you should make light work of the first MIO boss - leading you to the Silo Access Badge.
2. Crow
Item Unlock: Harvester ability
Despite the potential to come across Crow quite early in the game, they're one tough enemy to defeat. It might take one or two goes to start to learn their movement pattern.
The first move in Crow's moveset sees them drop to the ground. As long as you avoid their landing area, which is easy, this is the best time to deal as much damage as possible to the Automated Reaper. Even when it stands up and spins, it doesn't deal any damage, so don't be afraid to keep hitting until it disappears.
From here, Crow has a sweeping in-air attack and throws projectiles, so during this phase, don't worry about fighting; simply keep your distance and prioritize evading Crow's own attacks. Maintain this slow and steady rhythm to eventually defeat the boss. Things do speed up in the second phase of the fight, but the premise is the same.
3. Flora
Item unlock: Aviaries Passepartout
Like Egis, Flora is an essential boss to defeat to progress in the game, as killing the sentient Pearltrap reveals the Aviaries Passepartout, a crucial key for unlocking more of the map and the Dodge ability.
To get past it, you need to avoid its arms and a poison spit attack, both of which are foreseen by visual and audio cues. When Flora starts to raise its arms, vines, stalks, whatever you want to call them, at the back of the screen, you know an attack is coming. When you hear a screech, it's a good sign that a poison attack is on the way.
For vine attacks, it's best to move to the left of the screen and be prepared to jump. These moves vary throughout the battle, but this is the best method to avoid them all. Staying to the left should also work for most poison attacks, but be cautious of those that project further along the battleground.
Like with many of these MIO bosses, deal as much damage as possible to Flora between their attacks, perhaps even with the Kinetic Thrust Modifier equipped.
4. ACAT
For your fight with Acat, be sure to have the Dodge ability unlocked, which is obtained from the Strange Tube in the Aviaries. If you've already fought Flora, you'll have the key to the Avaries, but you can still get there without it.
With Dodge equipped, bait Acat into attacking by moving side-to-side, and deal damage while he's on the ground. For the most part, you want to jump while Acat prepares his next attack. The main exception here is when he jumps in the air. During these moves, stay on the ground until he attacks, and then jump. Try not to waste your double jump, so you can stay in the air as long as possible, and use Hairpin if you come unstuck.
5. Calderon
If you've played Silksong, Calderon's boss battle plays out similarly to that of Fourth Chorus in that you must attack its moving head while it attacks with its four arms. The trick here is to keep your eyes on the machine's claws while attacking its head. When they turn red, they're about to hit, and you can tell where from their current position.
When the grabbers are up high, they'll come down and hit the ground. When they're to the side of Calderon, they'll swing into the middle. simple, right?
Wrong. Where the challenge comes in with Caldern is during the second phase of the fight, and we actually found this one of the hardest bosses to crack. Partway through, you'll be whisked into the air by a constant updraft, which makes it much harder to attack. In fact, we found some attacks just weren't hitting at all, which makes this section incredibly frustrating. Our tip here is to take your time and stay in the top corners of the screen as much as you need to. Only attack Calderon's head when you are safely underneath, as these attacks are most likely to land.
6. Atmos
To defeat Atmos as easily as possible, you'll probably want the Sail ability, which can be found in the Strange Tube at the top of the Bell Tower.
Atmos starts as a snowman, and while he may look cute, he quickly transforms into a more deadly form. Don't miss your opportunity, then, to deal some quick damage to him in his snowman state. Once he transforms, you can stay fairly close to him, dealing as much damage as possible while he's still, and jumping up and over as he attacks.
While Acat looks to have quite a complicated moveset, it's all mostly harmless - he just moves around a lot.
Acat's most deadly attack, however, is when he moves to either end of the battlefield and shoots a rapid-fire projectile attack. This is when you need to use Sail. While you can simply jump over most of Acat's projectiles, or evade the ones dropping from above, this constant stream of ice bullets doesn't give you a chance, so jump above it and stay there, landing near Acat to deal some damage when he's done.
7. Nabuu
Nabuu is as deadly as it is beautiful, and this is probably the most complex battle you'll have faced so far, thanks to its changing nature.
The phases where Nabuu is on the ground are relatively easy, as you should just stay underneath the deer-like creature, attacking its chest from below. This keeps you out of the way of most of its attacks.
However, Nabuu will move to the back of the screen for the second phase, during which time you must instead avoid dropping explosives and a rising flood. For this, you'll want to attack the purple flowers to stay in the air, while utilizing your Sail ability between attacks.
The only other attack to be aware of is when Nabuu channels its horns into the ground, using them to attack from other parts of the screen. These can come from the ground or from the sides of the arena, but the white glowing strands give you plenty of warning.
8. Sawlong
Sawlong isn't a boss in the technical sense of having to fight it. Instead, this dangerous creature is to MIO what a boulder might be to Crash Bandicoot - you just have to keep from winding up underneath it.
The main thing to keep in mind here is that you are going to need to use most of your unlocked abilities, and if Sawlong does catch up with you, it's just a case of memorizing the route ahead. Our only advice here is just to focus on your reaction time - and keep moving.
Sawlong appears twice during a full playthrough of MIO; once in The Vaults and once in The Pit.
9. Anra and Dr Halyn
This is where things start to ramp up. This two-stage battle might seem like it's over when you defeat Anra, but Dr Halyn has other plans. Fortunately, the second phase is actually the easiest bit here, and you just need to avoid the mechanical arm's ground pound attacks while continuing to damage the now-dead Anra in its hand.
The most difficult part comes first, as Anra is quite a mobile enemy. Here, you want to stay close to Anra as much as possible, utilizing your dodge when needed, as a lot of Anra's attacks are projectile. Staying in close means they can't actually hit you, while you deal considerable damage. While Anra's early attacks are melee, staying in close still seems to be the trick here.
Also, between Anra's first and second phases, they gain a shield. To break the shield, simply attack the yellow orb in the mechanical hand, and it will eventually break.
10. Friends
The actual Friends fight itself isn't all that difficult; what's tough here is that you're also climbing a wall at the same time as battling this fiend, so your coordination might be a little all over the place at first.
Once you've got the hang of that, though, just keep close to the slimy blob that is 'Friends' and deal as much damage as possible. Things only start to get a bit harder when their gooey extremities start to take over the screen, but you can attack the blobs on the end to get rid of them.
11. Lombre
Another slimy dude, Lombre is another enemy for which you're going to need to have mastered your dodge ability. However, his battle is actually pretty simple.
You've probably seen the likes of this before. Lombre digs through the ground, and you'll be given visual clues as to where he'll come from, so avoid him, then deal damage when he stops. Occasionally, he'll leap in from the side and slide, which is when you should use dodge, dealing damage when he hits the opposite wall.
The only thing that varies here is that, mid-way through the battle, Lombre starts to use poison. This is pretty easy to avoid for the most part, aside from when it rains from above. When this happens, there is usually just one gap. If you miss it, just be ready on the dodge button.
12. Vlad
In theory, the Vlad battle is quite simple, but the patterns and movements might take some getting used to. Still, at least Vlad himself doesn't attack you.
Instead, this enemy pulls spikes and projectiles out of the walls of the circular battle room. So, while you're attacking his body in the center of the field, you must also be aware of everything going on around the edge.
One of the key moments here is when the walls start to vibrate, signalling that they are about to spin. When this happens, you need to jump to avoid the spiked areas. You won't be able to attack Vlad during this time, so just concentrate on avoiding taking damage - especially when the electrical current comes into play.
13. Ancile and Targa
If you thought Egis was easy, just wait for Ancile and Targa, who are basically just two more Egis'. The toughest part about this fight is that it's pretty relentless. Ancile and Targa don't spend that much time on the field together, and when they are, you can focus on just one, as they move mostly in unison. When separate, though, you don't get much respite from their constant movement.
14. Debby
This is your classic disappearing ground fight. Debby drops explosives, which destroy the floor beneath you, meaning you need to pay attention to where you're running and landing, using double jump to get over large gaps. Meanwhile, Debby relies on projectile attacks, with the most powerful being a rapid-fire attack from the edge of the screen. If you place yourself correctly, though, you can land on Debby and deal constant damage during this move.
15. Poltergates
Poltergates might be our favorite MIO boss, aesthetically speaking. Functionally, he's a bit of a challenge. By this point, these bosses are starting to put together a lot of the mechanics you've already gone up against, and Poltergates is a good example of that.
His earliest challenge is releasing a few standard foes into the battlefield from the world outside. Then, though, he manifests another version of himself. Unlike Ancile and Targa, though, these two move independently but simultaneously, giving you a lot to think about. Beware of the attack that one of them drops from above, because you'll need to evade that while also being aware of the second 'Gates.
16. Sol and Vin
You're prepared now. As we get nearer to the final boss, you've had enough practice to deal with everything this pair can throw at you. Literally, when it comes to throwing their swords.
Very early into this fight, the ground reduces to just the small circle in the center, meaning you're going to need to combine jumping and dodging. Sol and Vin do behave in a relatively predictable way, with one swinging while the other slams, so once you get used to this, that's most of the fight dealt with.
With their health almost at zero, the ground completely disappears, at which point you have to rely on your Hairpin ability to stay in the air while attacking. Since there's not too much damage left to deal, we'd recommend taking this section slowly, concentrating on staying afloat, and only attacking when it's safe to do so.
17. The Keeper of the Heart
As the final boss of the main game, The Keeper of the Heart has the most health of any boss you've faced so far, meaning this is a long fight. Endurance is more important than anything, as the boss's combination of jab, projectile, and slam attacks is nothing you haven't already seen before. In fact, we'd say your best bet here is to take your time, learn the moves, and, most importantly, reduce as much damage to yourself as possible.
Given the length of this fight, you'll want to have every possible layer of Protective Coating at your disposal, including the Protective Overlay Modifier. Then, deal damage to your opponent mostly after slam moves, when they are on the ground for a slightly longer period of time.
With these handy tips on beating the challenging MIO bosses, you should have no problem rolling credits on this beautiful metroidvania game - and finding that 'true' ending, to boot. We'll keep adding to this list as we progress.