Actually, they are the same. The same plot and the same atmos.
Storytelling and emotions are kind of different and it is due to cultural differences.

Regardless of the scenario difference of these two movies, both concentrate on social differences and greedy people struggling to hoist themselves to an upper and wealthier group, even though they have to step on their values and humanity.

Both dramas revolve around cheating partners. In both dramas, female leads are very powerful.
In total the World of Married has a more coherent story and better endings

Both movies narrate the kidnapping story where the female lead struggle to survive. Interestingly, the FL in both movies are Kang Ye Won.

This is Korean vesion of this drama.
Not ocmpletely the same storyline but both reveals a relationship between a minor and a teacher.

Mistress is about four women with scandalous background teaming up to do an errand. Both series revolve around 4 women with different background gathering to solve a problem. However mistress has more criminal and mysterious atmosphere.

Both are based on revenge theme where some women with different backgrounds team up to take revenge of their abusive husbands.

Both scenarios are almost the same with little difference. Moms trying to bring back dad and try to settle her child after her death

Both scenario are the same with little difference. Moms trying to bring back dad and try to settle her child after her death

Both movies depict story of a disaster and struggling of people to be survived.
The Exit is mostly focused on the escape plan of a couple (not really couple) but Ashfall is more team oriented

Both movies portray a disaster in a city and struggling people to be survived.
Both movies benefit form great actors and scenario as well as eye catching special effects.

Both movies reveal a catastrophe in a confined place (tower) and FL and ML are struggling to save their lives and survive from fire or gas.
The difference is the Exit has few spice of comedy.
The Tower movie has better movie enjoying from splendid special effects.