Well, I'm a "fanatic" of metroidvania games and I have played quite a few, mainly on the Nintendo Switch, and I believe I have a good opinion to give now that I have completed Metroid Dread with 86% item completion in 12 hours.
(I completed it in 13 hours and 13 minutes with 100% item completion, unlocking all the images from the art gallery. After that, though, besides doing hard mode/speed run, the game doesn't have anything else to offer. There is no other mode and the hard mode just makes the enemies hit you harder).
Let's start with the positives -
Very good graphics, perhaps the best 2.5D graphics I have seen in a metroidvania game, even better than Bloodstained: Ritual of the Night and Ori and the Will of the Wisps.
The gameplay is fast-paced and quite action-heavy, especially when you acquire additional abilities/power-ups, giving you the feeling that you are playing a hack and slash game with the speed at which you explore the areas. It's the first time I've seen a parry mechanic being implemented in a metroidvania game, which you often have to use multiple times to progress through the story. Overall, if I compare it to older Metroid games, the main problem that existed was that if something got close to you, you had no way to keep them at a distance to attack them with your weapon. Here, that problem has been solved in a very good way. There is also the slide mechanic that allows you to pass through narrow passages without needing to crouch, or for those who know how to use the Morph Ball, resulting in being able to maintain the speed you have when running and creating incredible scenarios to avoid enemies and intense chases with the EMMI that hunt you down.
The map is huge and the overall game duration from start to finish, if you ignore collecting items and only focus on the story, I would say it will take you around 6-9 hours the first time you play it without any help. Otherwise, if you go for 100% completion, I would say it will take around 12-15 hours.
There are cutscenes/cinematics that you rarely see in metroidvania games.
The elite/boss fights, for the most part, are good. The elite fights, not so much because they used many of the same enemies without making any changes to the way you face them. On the other hand, the boss fights, most of them are good, some I would even say are unique because you need to use the parry and slide mechanics.
The EMMI, perhaps in my opinion, the best part of the game and the only feature in a metroidvania game that you won't see elsewhere. The EMMI are robotic enemies that guard specific areas on the map and you have to pass through them. They cannot be defeated until you find a special power, so you have to either pass by unnoticed or if they spot you, you have to run for your life to a safe place. There are a total of 7 EMMI and each one becomes even more difficult. If they catch you, you have a chance to escape with the Parry, but it's quite difficult to time it right. However, if you manage to do it, personally, it was very satisfying for me. Overall, the whole experience reminds me a bit of Metal Gear Solid 2.
The UI (menu, map, character statistics) is very good and clean, especially the map, which is incredibly detailed, perhaps the best map in a metroidvania game.
The loading times between rooms are faster than even Hollow Knight, which I thought no game could surpass. Not only that, but it's also more realistic. If you leave one room and immediately go back, the enemies you killed previously won't be there. Additionally, it remembers what you did in the previous room. For example, if you used an ability with a duration or range and then changed rooms, it will continue to work. This is the first time I've encountered this feature. Even the enemy attacks can change rooms if the gate you passed through was open.
Saving is quite fast, and the FPS is stable without any lag, both in docked and handheld mode.
The game plays amazingly with the camera capturing specific moments and areas you pass through. The power-ups are quite good, and you always feel that they are worth it when you acquire them. For those who have played previous games in the series, most of them are the same except for four new abilities.
With the 2019 edition of the Switch, the game lasted about 4-5 hours with medium brightness and sound, which is quite good considering the graphics it has.
Let me also mention the negatives -
One negative, and I will mention it, is the price. Yes, paying 50-60 euros for this game's duration is a bit tragic when big companies as well as indie developers have flooded the market with metroidvania games at much lower prices while being almost equal in quality to Metroid Dread. Maybe I will change my opinion if they add something extra in the form of free DLC, like Hollow Knight and Bloodstained have been doing for a while.
Related to the price, when a customer pays such a large amount, you would expect the game to have everything included, including other languages. But it's only available in English, and I'm not even mentioning the voice overs because those can't be done in another language since they speak something that doesn't exist, so you read the subtitles. But the subtitles are only in English. Personally, it doesn't bother me, and probably not many Greeks either because we rarely have Greek subtitles in games, and we have gotten used to it. But I mention it as laziness on Nintendo's part for not offering the simplest thing at these exorbitant prices.
There will be moments when you simply won't know where to go because many breakable walls don't have any indication that they can be broken. This will mainly be a problem at the beginning when you don't have the ability to scan the area or because you don't have rockets to spend, and you'll be thinking about where and when to use them. It happened to me, and it took me 20-25 minutes for something very silly. I watched a one-minute video to help me, and it had 150,000 views, so I wonder if I wasn't the only one who encountered the problem.
Unfortunately, you can't play with the D-Pad/Arrow keys. I always play metroidvania games with them, and this time I couldn't. The worst part is that you walk and aim with the same analog stick, making battles more difficult than they should be. However, I understand their decision because 95% of the buttons are already used for other things.
Music, I expected something better and more songs. In Metroid Fusion that came out on Gameboy Advance, I felt that there were better tracks. Metroid Dread also has some very good ones, but they didn't stick in my mind like in other games.
As for backtracking, at first it will frustrate you, but once you finish it and find all the teleporters and use them at least once, then and only then it unlocks the option to choose where to teleport instead of only being able to teleport to specific points that correspond to their color. But still, I would have preferred to have this option from the beginning, as is usual in most metroidvania games that have been released in this decade. (minor flaw)
Conclusion, if you want to start with metroidvania games and you care about every penny in your pocket, I would say don't get it. It's just too expensive. With the same amount of money, you can get 2 or maybe even 3 very good metroidvania games when they're on sale, like Hollow Knight, Bloodstained, Ori and the Will of the Wisps, SteamWorld Dig 2... and the list goes on.
But if you're a fan, I believe it's a fantastic choice, especially if you're like me and have played most of the good metroidvania games.
I will change my rating to 5 stars if additional free DLC is added to provide more gameplay, like a boss rush mode or additional unlocked areas.
Update: I finished it 3 times, once in hard mode and twice in normal mode. I did one "speed run" for the gallery (4 hours). The positive thing about this whole experience is that even after 3 times, I would play it again. The "sequence breaks" it has allow you to explore the areas in different orders in many ways, making the whole game feel more open world, similar to Super Metroid. Besides that, because the character is fast, you don't feel like you're dragging at the beginning of the game and you quickly surpass the boring parts to reach the power-ups.
On the negative side, I would say the boss fights are simply too easy, except for two exceptions, and this is when playing in hard mode. The other problem I encountered, after creating the third save file, is that the loading screens became longer, the transitions between certain rooms became slower, and I experienced occasional stutters. I don't know exactly what's happening, but the game seems to struggle more with 3 save files.