Both movies are early New Taiwanese Wave productions made by Chen Kun Hou-Hou Hsiao Hsien duo with Doze Niu cast as main character. Both stories focus on mundane life of youths and grave consequences of lack of communication between family members
Both shows tell the story of young genius officials who use their smarts to fight injustice and solve mysteries.
Both shows focus on military training of unique youths - in case of AMA it's a woman crossdressing as her brother, in case of Decoded it's a math genius
Both shows use the same idea of mistaken identity and employing a (not exactly qualified for this position) stand-in for a dead person.
Both shows focus on swapped identity and how leads cope with being forced to live with someone else's family and kids.
Both shows are about male leads who time travel to the past, befriend royals and start impacting the past using their modern knowledge.
Both movies tell the story of three oddballs and their slightly absurd journey. Both productions have awesome OSTs
Both movies tell the story of clumsy air-headed women who do their best trying to fulfill their dreams and become flight attendants.
Both shows are heartwarming, healing family shows that tell two stories simultaneously - the past, and how it affected the present.
Both productions show life and love of immigrants in either mainland China (Beautiful Life) or Hong Kong (Comrades). First half of A Beautiful Life is quite similar to Comrades: Almost a Love Story as it features not-quite-romance between a naive and warm-hearted male lead and business savvy female leads.
Both productions start off with protagonists trying to cover up murder. As a consequence, these deaths attract attention of unconventional police officers who try to figure out who and why killed these people.
Both movies feature eccentric men who who wander in the desert to find what they're looking for. Although plot isn't really that similar, these two productions give off similar vibes