The center of the stage is occupied by a building with two awnings which act as soft platforms. Stepping on the awnings makes the sign tilt, and stepping on them two more times makes them drop and become unavailable; they get automatically restored after a short time.
On the right there is a light blue house with a festoon over it, which acts as a soft platform. On the left there is a yellow house: the tree over it provides two soft platforms which react to the weight of fighters and items.
Several more buildings appear but because they are beyond the lateral blast lines, they cannot be accessed during gameplay.
At times a warning sign appears near the side of the screen, signifying that a car or van will pass by the bottom of the stage. The vehicles can hit and damage fighters, as well as destroy or activate items like crates. Every vehicle deals 30% damage, but their other properties differ:
The background features several more elements: a hospital, a hotel, a backhoe, and a hill with some houses (including Ness's) and a meteorite on top. On the foreground, outside the normal camera view, there is a white canopy and some bicycles. On the right of the stage, slightly beyond the blast line, there is a sign with a warning about the black van.
Onett returns in Super Smash Bros. Brawl with multiple changes. The stage prefix is now EarthBound: Onett. One change in the stage is that the right edge of the left building's roof can no longer be grabbed. Also, there are slight lips on the both sides of the house on the right. This prevents characters against these walls from jumping to avoid cars. However, the cars in this version of Onett deal highly reduced knockback, lacking KO ability at realistic percentages unless very close to the walk off edges, although their damage output has not been decreased and they can still disrupt gameplay. Another slight change to this stage is that the red cross on the building of the Hospital has been removed, most likely due to issues about the Red Cross emblem.
The warning sign on the right side of the stage is only readable in Brawl when the Devil assist trophy moves the stage to the right or when an unrestricted camera hack is in use. In Melee, it can be read simply by standing close to it, pausing and moving the camera.
In SSB4, the vehicles lose their unique launching properties.
In Ultimate, The design of the buildings on the background, now match more closely to their appearance in EarthBound.
Ω forms and Battlefield form
In Super Smash Bros. Ultimate, the main platform of the Ω form and Battlefield form is reminiscent of the drug store from SSB4's Ω form, such as the floor resembling the building's roof top and the walls resembling the bulding's facade; however, the drug store, as well as the rest of the town, are in the background. The platform does not extend below the blast line and is resized and reshaped to match Final Destination and Battlefield, respectively. The three soft platforms of the Battlefield form are multicolored canopies.
With hazards off in Ultimate, the cars never drive by and hit the fighters, and the Drug Store canopy and sign do not collapse.
The buildings that act as the main platforms of this stage include a drugstore, which act as item shops where Ness can withdraw and deposit money with an ATM and save the game with a payphone; the blue house on the right, which bears resemblance to how small houses were designed in EarthBound; and the yellow house on the left, which is not based off any house in EarthBound.
Cars, including Taxis, drive along the streets in the cities, but unlike in this stage they stop when in front of Ness until he gets out of the way. The black van, which in EarthBound never appears in Onett, belongs to the Runaway Five, a band with debts that Ness and his friends help repay. To show their gratitude, they offer Ness a ride from Twoson to Threed. The bulletin board which warns players about the van is inspired by similar bulletin boards in EarthBound which feature miscellaneous messages.
Some of the elements in the background and outside the stage's bounds include the Onett arcade, where Ness defeats the Sharks and their leader Frank Fly; a hospital, where status aliments including unconsciousness can be healed; a hotel, where the party's HP and PP can be fully recovered; a backhoe resembling the one in Dusty Dunes Desert, and a canopy in the stage's foreground that resemble the shops of Burglin Park in Twoson.
The very back of the stage also depicts the steep cliffs at the north of Onett. These feature Ness's house, Porky's house, the entrance to the cave that leads to Giant Step, and the meteorite which crashes on top of the hill at the beginning of EarthBound, thereby kickstarting the plot; however, their positioning is different with respect to EarthBound.
The Ω form in SSB4 takes place on top of a wider version of the drugstore with some flowers and a trash can, which is reminiscent of the first meeting between Ninten and Lloyd in EarthBound Beginnings, where Lloyd is hiding in a trash can on the roof of Twinkle Elementary School.
In the early metagame of Melee, Onett was considered tournament legal as a counterpick stage. However the stage is now banned in all games it appears in. The reasons for banning are the same across games; the walls allow for infinite combos (this problem is more prevalent in Melee and not at all in Smash 4), and the stage hazards of the cars can disrupt gameplay and easily allow for early kills. The lack of a lower blast line also removes the edge guarding component of characters; the low ceiling at the top of the stage and the walk-off blast lines also can allow for very easy and early KOs.
Super Smash Bros. Melee
Super Smash Bros. Brawl
Super Smash Bros. for Wii U
Super Smash Bros. Ultimate