The Destroyer has 3 attacks too (probes, contact, and body lasers), the Eater of Worlds, Eye of Cthulhu, Queen Bee... There's a lot of full fledged important bosses with very few attacks too.
You have a point for the Destroyer, but for the other bosses it makes sense because they are found earlier in progression.
Dreadnautilus is far more complex than many other bosses. It has summons, shoots projectile barrages, has a charge attack, and can even reflect projectiles.
I wouldn't call Dreadnautlius far more complex, since everything you mentioned is pretty much the same as with other bosses. Eye of Cthulu, Brain of Cthulu, Queen Bee, Deerclops, Wall of Flesh, etc. all have summons. The Destroyer, Retinazer, Skeletron, Skeletron Prime, Duke Fishron, Empress of Light, Queen Slime and Moonlord have a decent bit of projectiles too, and Eye of Cthulhu and Queen Bee both charge. In fact, Eye of Cthulu has half of what you mentioned, and it's the first boss in progression. The only "unique" thing Dreadnatulius has is reflecting projectiles, but that's one attack. Compared to minibosses (what Dreadnatulis is, and what he should be in his current state), it's a different story. He has around the same amount of attacks as a miniboss like Pumpking, and that's because Dreadnatulius is designed around being a miniboss (in his current state at least).
You could argue that a new player wouldn't do many of the things required to summon other bosses. There is no indication ingame that you should go to a Glowing Mushroom biome, find the rarely spawning Truffle Worm, capture it with a net, and then take it to the ocean and go fishing with it.
Yeah, that's why I said Fishron was an exception lol.
There is also no indication ingame that you should look for the Prismatic Lacewing in a Hallow forest biome and that killing it will summon the Empress of Light, unless you accidentally do that already or it dies to an offscreen projectile.
Yeah, there's a chance that a new player will kill a lacewing and summon the boss. There's not really an indication to do that, but it can still happen.
And also, Queen Slime's summon is something you come across by accident, new players likely won't notice it looks slightly different to other crystal shards.
Your right, honestly. Should've thought more about that one.
Plantera and Queen Bee's spawning things you have to destroy also just look like loot at first to a new player who hasn't experienced them before.
If a new player enters a hive, then they are definitely summoning Queen Bee, that's kind of what's she's known for. As for Plantera, assuming a player is looking for Life Fruit (the jungle grows restless), they might break the bulb and try to fight her afterwards.
Lots of things in Terraria aren't explained until you've done them, and I'm sure some players will eventually be fishing on a Blood Moon if they don't feel like fighting enemies.
I doubt a new player who's getting killed by enemies left and right will think "Hey what a perfect time to start fishing for six minutes."
And if not, then just get the Guide to mention fishing during a Blood Moon bringing out powerful valuable enemies.
That could be done, but that isn't actually a thing in the game, which is why I've said that Dreadnatulius has boss potential, but isn't there yet.
Frost Giants and Sandstorm Elementals are enemies more powerful than others which spawn during a certain event, much like Nailheads and Eyezors being unnaturally tanky for Solar Eclipses, or the Flying Dutchman and Pirate Captain being unnaturally tanky and high-presence for their own invasion events, which happen naturally, much like Blood Moons.
Maybe we got confused on the wording here, or maybe I am getting confused on the wording right now, because the line between a miniboss and a powerful enemy is pretty foggy. I would consider Frost Giants, Sandstorm Elementals, Nailheads, Eyezors, and Pirate Captains to be powerful enemies because they don't have many, if any, useful drops. However, a Flying Dutchman would be a miniboss because of the health bar. Actually, since the Flying Dutchman and the Flying Saucer have health bars, then Dreadnatulius and Mothron deserve one too. That doesn't make them bosses though, but just a thought.
The same can be said for Mothron and the Flying Saucer, which also spawn during specific events and have special drops.
Dreadnautilus spawns during the Blood Moon, but so do many tanky minibosses such as Undead Merman, Wandering Eyes, The Groom, The Bride, Blood Eels, Hemoglobin Sharks... There's a lot of definitively miniboss enemies that are tanky and more dangerous than the rest of the things in their respective event.
Yeah, there are. So we should call them powerful enemies, not minibosses, because most of the things you just mentioned are just tankier versions of other enemies and have little useful drops.
But Bloodnautilus is more complex than them, and on par with the Flying Dutchman, or Flying Saucer, imo, and at least deserves a health bar.
Yeah, Dread (lets just call him Dread) deserves a health bar now that I think about it, but he shouldn't be a boss in his current state. He'd need more attacks, more drops, and a better way to summon him before we should think about him being a boss. But honestly, Dread being a miniboss is fine too. That's what he was DESIGNED for, and there's no need to change that. Again, if it ain't broke, don't fix it.
