Nargisa

Similarities :
Time Travel
Girl fell first
Both male leads died multiple times
Both girls tried to save their love interest
Both met in the highschool

Similarities:
Both are lgbt series based in china ,
They both are not blood related
Both are miniseries

Difference:
The first one is the brother who adopted him and the second on is they're step brothers

Similiar :
They're both step brothers
Both are not blood related

Difference :
Both are from different countries

Both are the same survival show , one is the original version and the other one is compilation , C Refer to China

Both are the same survival show , one is the original version and the other one is compilation , K Refer to Korea

I-Land season 2 :N/a is a survival show from the same agency as planet b aka boys planet II ,
Both are from south korea

Both are k-pop survival shows ,
Both are from south korea
Their network channel are same Mnet
Both are idol compitition show

It's because both are the same work, the first one is drama and the second one is special episode of this drama