The series is known for its combination of humorous and emotionally evocative tones.[1] Itoi wanted to tell Mother 3 through a technique that swapped the active player-character, which he first attempted in EarthBound.[2] The two games also share similar visual styles,[3][4] both with psychedelic battle backgrounds and cartoonish art.[3] While Mother 3's music is both similar in tone to its predecessors and completely new, it features similar sound effects.[3] EarthBound characters such as Mr. Saturn recur, and RPGamer wrote that Mother 3's final chapter is "full of blatant links" between the games of the series.[5] Mother also shares similarities with its sequel, such as the game save option through phoning Ninten's father, an option to store items with Ninten's sister at home, and an automated teller machine for banking money. Additionally, the members of the party follow behind the protagonist on the overworld screen in the first two games. Ninten's party members in Mother are analogous to those of EarthBound in style and function.[6]
While Mother's battles were triggered through random encounters,[7] EarthBound and early Mother 3 shared battle scene triggers, where physical contact with an enemy in the overworld began a turn-based battle scene shown in the first-person.[8] Apart from Mother 3's rhythm and combo battle mechanic, the two game's battle systems are similar.[3] Mother 3 also retains the "rolling HP meter" of EarthBound (where health ticks down like an odometer such that players can outrun the meter to heal before dying/fainting) but removes the feature where experience is automatically awarded before battles against much weaker foes.[5] Recurring through the series is its signature "SMAAAASH" text and sound, which show when the player registers a critical hit.[6]
Some characters are present in multiple entries of the series, such as Giygas, Mr. Saturn, and Pokey/Porky. Giygas is the primary antagonist in both Mother and EarthBound. The alien creature's emotional complexity deviates from genre norms. Giygas shows internal conflict in Mother and has no appearance but as an "indescribable" force in EarthBound's final boss battle.[9] In both final battles, Giygas is defeated through love and prayer instead of through a tour de force of weaponry, unlike the endings of other period games.[9] Nadia Oxford wrote for IGN that nearly two decades later, EarthBound's final fight against Giygas continues to be "one of the most epic video game standoffs of all time" with noted emotional impact.[10] This battle's dialogue was based on Itoi's recollections of a traumatic scene from the Shintoho film The Military Policeman and the Dismembered Beauty that he had accidentally seen in his childhood.[11] Oxford wrote for 1UP.com that Itoi intended to show the alien's yearning for love in "a manner ... beyond human understanding".[9] Despite EarthBound and Mother 3's dissimilar settings, the Mr. Saturn fictional species appear in similar Saturn Valleys in both games. The Mr. Saturn look like an old man's head with feet, a large nose, and bald except for a single hair with a bow. Though they are a technologically advanced and peaceful species with a pureness of heart, they are under constant attacks from encroaching enemies. Nadia and David Oxford of 1UP.com considered the Mr. Saturn to be aliens despite their human-like and fleshy appearance, as described a piece arguing the central theme of aliens in the Mother series. They compared the Mr. Saturn to Kurt Vonnegut's Tralfamadorian alien species.[9] Finally, Pokey begins as Ness's child neighbor who "cowers" and "refuses to fight" in EarthBound, but grows into a "vicious control freak with no regard for human life", Porky, by the end of the series' Mother 3.
