Moon Lord is a badly designed boss

[itchylol742]

• He just follows you around without any specific movement pattern, while other bosses have interesting movement patterns like the Twins or the Destroyer. Even the Wall of Flesh is interesting because having to keep running is an interesting mechanic.
• He takes up the whole screen which makes it hard to see projectiles, since him and the projectiles are the same color pallette
• When he opens his hands you have no idea what attack he's going to use. There are three: Shooting large eyeballs that float for a bit before flying off in a direction, shooting 2 projectiles directly at you, or shooting a bunch of drunken projectiles that randomly change direction midair.
• There's no way to know where the floating eyeballs will move, and they move so quickly you can't dodge them after they start moving
• The two projectiles attack is so fast you can't react fast enough to dodge it. Some other bosses have fast projectiles, but at least you can predict them like Retinazer's laser attack, you know it's going to shoot a laser directly at you. But since Moon Lord has 3 different attacks you don't know
• The drunken projectiles move unpredictably so you can't dodge it
• His hands and eye and closed 75% of the time so after you kill the hands, you just have to wait for his eye to open so you can shoot him
• There are three points he can attack from: 2 hands and his eye, keeping track of all three is very hard. It's actually worse than Skeleton Prime who has 4 limbs and a head because each of Skeleton Prime's limb only has one attack, while the hands and eye keep changing their attack, which as I pointed out earier is impossible to know what attack they're going to use.

Now compare the Moon Lord to a boss with good design like Duke Fishron. The fight against Duke Fishron is fun because he doesn't take up the full screen so you can see his attacks. Also, his attacks give you enough time to see and react to, like the sharknados, the homing bubbles, and his charge attack. Every playthrough I look forward to the Duke Fishron fight because it's hard but fun, while I dread the Moon Lord fight because it's hard, but not fun.

 

[Dapling]

His eyes DO actually have different patterns for different attacks, you just have to pay attention to three at once, so it doesn't help too much:

• Pupil looks at the player: Fires two bolts.
• Pupil stays in the center (only hands): Creates the large eyeballs.
• Pupil stays in the center (only head): Shoots the notorious Phantasmal Deathray.
• Pupil moves around in socket crazily: Shoots the swarming homing projectiles.

The first phase isn't actually that badly designed, it's the second phase (with the True Eyes) that needs work because of how stupidly short their startup is compared to the first ones.

 

[Sciffles]

His hands DO actually have different patterns for different attacks, you just have to pay attention to three at once, so it doesn't help too much:

• Pupil looks at the player: Fires two bolts.
• Pupil stays in the center (only hands): Creates the large eyeballs.
• Pupil stays in the center (only head): Shoots the notorious Phantasmal Deathray.
• Pupil moves around in socket crazily: Shoots the swarming homing projectiles.

The first phase isn't actually that badly designed, it's the second phase (with the True Eyes) that needs work because of how stupidly short their startup is compared to the first ones.

I agree on @Derpling Ω with the first phase. The second phase may be a bit hard, especially with the small attack charge, but if you study it carefully, it’ll make it I bit easier.

 

[The Storm]

I'm pretty sure the attacks always follow the same pattern, but the first phase is fine, it's the second phase that can be a pain, but again all the attacks follow the same pattern, but it can be tricky when there's 3 deathrays all heading in different directions.