Since we are going through this fad of people getting trapped in videogames or transported to magical worlds, let me give you some tips that clearly make some executions of this concept, better than some others.

(1) Make it clear right away what does being transported to a different world means for the characters, as well as what objective they have. 
- Good examples: In Twelve Kingdoms the characters immediately try to find a way to get back home. In No Game No Life, the siblings immediately state that they are happy to be here, since they hate the world they came from. 
- Bad examples: In Sword Art Online the characters behave in whatever way it suits the plot. First they like being in the videogame, then they want to get out, yet they still behave as if they love it, and even when they get out, they immediately run back in. In Re:Zero the MC immediately runs after waifus without ever making it clear if he wants to go back or stay here. In Grimgar, the heroes don’t even know what they are supposed to do; there is no objective other than making money for buying food every day. In Log Horizon, they want to get out, but quickly give up and head for silly adventures instead. 

(2) Define what failure means in this new world. Do people die when they are killed or do they respawn indefinitely? Do they feel pain or are they immune to it? And I don’t mean psychological pain; any show can have that, Pokemon included. I am talking about physical pain, which is something many shows stay away from. If there is no death or pain, then there is no tension. Both elements need to be present, otherwise nothing feels serious. This is why Sword Art Online and Re:Zero are bad examples, while Grimgar is a good one.

(3) Define the world in what makes it different from our own. Shows like Re:Zero and No Game No Life pretend to be different realities, when they are just generic fantasy realms full of otaku stereotypes that exist purely as fan service. Any show that is made to look like harem videogame suffers from this. Something like the 12 Kingdoms on the other hand places a lot of effort on why that setting is completely different from our own and is free of silly fetishes that the otakus expect to see. 

(4) Don’t make the heroes overpowered, because it saps away the thrill of being in a different world. I never felt any actual threat from the challenges in Sword Art Online or Log Horizon, since they are super powerful as well as a plot armored. What’s the point of being in a different world if it doesn’t translate into a bigger challenge than our own? The weak characters of Grimgar and Twelve Kingdoms on the other hand were making every encounter with enemies to be exciting.

(5) Show some sort of interaction between the worlds. Don’t just have the characters moving in and out without everybody else reacting or being affected somehow by this event. Without interaction then the whole thing might as well be an illusion or a dream and everybody is a chuuni. The only good example I can think of is Digimon, which clearly shows both worlds being connected and affected by each other. Every other story either never shows what is going on in our world, or it shows interaction but no actual change taking place (SAO, Gate).

(6) Show some sort of character change. Not necessarily development; just change in perspective. People are not thrown in different worlds and are not somehow affected by the whole event. In Twelve Kingdoms, the characters change their perspective by the end of their arc. In Digimon, their objective changes from getting back home to protecting both worlds. In Log Horizon it seems like they changed their goal from leaving to just leaving there, yet nobody seems to give a fuck; they are acting like it’s a fun game while still trying to get out. In Sword Art Online and Re:Zero they change but only in any random way that suits the plot before going back to simply playing videogames because it’s fun. And in Grimgar, they change when one of them dies, but they never had a perspective or objective prior to this. They were black sheets of paper.

https://www.youtube.com/watch?v=VbI9JpOlbeY