Here are the Myanimelist (MAL) links for each anime:
Re:Zero
No Game No Life
KonoSuba
Sword Art Online
Since I already have set opinions of these animes, I'll try to be as unbiased as I can.
FISH OUT OF WATER
Let's start with the basic premise: the fish out of water concept. This is when a character is plucked from their world and plopped down in another one.
- With Re:Zero, Subaru is out shopping for groceries when he is taken to his fantasy world. The world he is introduced to has many different races, and he encounters trouble right off the bat. This concept is done well here. Subaru doesn't know anything about this world, but he adapts quickly. This is a good example of the concept done right. He learns the language or tries to. And he tries to adapt to its customs.
- No Game No Life has the sibling duo Shiro and Sora are taken by the childish god Tet to a world where games. They immediately take on an opponent. This duo easily takes on the fish out of water concept. They don't hesitate to participate in games. They aren't exactly the typical characters in a fish out of water scenario, but they are still surprised by their new surroundings. They don't adapt well to their new world. Instead, they push back and use their old world devices. They do learn the language and some modicum of the government, but they leave most of the heavy lifting to the side characters. This is a good example of taking the concept and adding a twist to it.
- KonoSuba starts with Kazuma being hit by a tractor in a feeble attempt to save a girl's life. The first world we see is actually limbo, the place between life and death. He is then taken to a fantasy world. The way he acts in his world is as if he assumes he is the hero of the entire world. He acts like everything will be handed to him, and with only video games as his basis of knowledge, it's obvious to see why. I disliked the way this anime handled the concept. It wasn't funny to see him act all pompous when things needed to be done. He didn't adapt to this environment, and it made me mad. Adapting to different environments is how you live life. Kazuma seemed to forget that.
- Sword Art Online has Kirito willingly putting on his NerveGear and entering the game. Out of the four animes, this is the one with the least amount of the concept. He isn't in a new environment; he was a beta tester and had already been exposed to the world. But then there are changes in the playing of the game. After all, the selling point for Sword Art Online is kids locked in a video game. That's the new part of the story. Kirito doesn't adapt to this, much like Kazuma. He plays solo and completely ignores the many deaths. That isn't how the concept is supposed to be taken. Again, adapting equals survival.
Out of all the animes, 'No Game No Life' and 'Re:Zero' use this concept the best.
Fantasy Elements
What's more important than the fish out of water concept in all four animes? Fantasy elements.
- Re:Zero introduces half-elves and magic and demihumans. These are all used fantasy elements, but Re:Zero introduces other elements that are unique. Take the mabeasts for example. They're creatures that look like they've been possessed. But we truly don't know a lot about them. I haven't seen creatures called mabeasts before. Sure, I've been possessed animals but not of the size of the White Whale. It's different. And while some elements of Re:Zero have been used before, there are different things that I haven't seen before.
- The game element of No Game No Life is completely different. Before this, I hadn't seen anything like that before. The game element was what drew me in the first place. The rules are complicated at times, but some games are simple. The games aren't just chess and Texas Hold Em, though. There are simple games such as rock-paper-scissors as well.
- KonoSuba shows a world with the typical fantasy elements. There are magical powers and guilds. The goddess part threw me off a bit because goddesses don't typically interact with characters. But it's still a typical fantasy world.
- The sword fighting in Sword Art Online combined with its unique bosses and items makes it stand out. Sure, the video game setting isn't unique, but some of the parts of the world are different. There isn't a lot of fantasy within Sword Art Online, but there's enough for it to be different. The bosses do set it apart compared to other fantasy worlds. But with the advanced technology, some might label this a science fiction world. To me, it is all set in a FANTASY video game, so it's fantasy.
The best fantasy world has to be 'No Game No Life's. It's completely unique and stands out from the crowd.
Main Character
What makes an anime? The main character, of course. I'm warning you now that this might turn into a bit of a rant.
- Subaru is a bit of a sore spot for me. At first, he seems great. He's a kind character who doesn't take it too far. But he turns into more of a brat as the anime goes on. At this point, he's redeemed himself, but he's still driving me nuts with his whining. At least, they haven't pulled the 'he has unlocked potential' on me.
- Shiro and Sora are funny. Much like the fantasy world of that anime, they're unique. They're silly and smart and NEETs. I kinda love them for that. They whine, but it's funny.
- Kazuma is whiny. He constantly complains why he doesn't get a sword immediately upon entering a guild. It made me mad. He thinks that everything will be handed to him on a silver platter. And I can't stand stuck-uppities like that.
- And, of course, Kirito. I didn't really see his godly powers until I watched Digibro ranting on him. So I can't definitively say whether or not he was overpowered. But he was annoying as a 'badass' brooder. He was so antisocial. Even an introvert like me thought he was too antisocial. He cut himself off from the rest of the world. And that's not healthy.
Shiro and Sora top this category with Subaru right behind them.
Personally, Re:Zero tops both Sword Art Online and KonoSuba.
Sword Art Online has a terrible history of being overdone, (Especially with the main character Kirito) and its second season has been sullied multiple times.
And KonoSuba simply didn't work out for me. The fanservice was overdone, and both of the main characters were brats. I couldn't stand them. The first episode really did it for me.
But No Game No Life isn't a bad anime. It has a lot of good elements. I'm just not a huge fan.
What do you think? Which of these animes is your favorite? Which one is the worst?