Multiplayer, as a mode, could be played in this versus mode or in a freestyle mode. The freestyle mode would just let both players dismount on any compatible level just like in singleplayer. Detailed below is the versus mode.

Multiplayer would only be playable with two players, and would be played locally.

All of this setup phase would be handled by Player 1. This would all be done on a large menu screen, accessed via the pause menu.


UNLIMITED
The game continues as long as both players see fit.

NUM. ROUNDS
Set a number of rounds to play before the game ends. Once the end is reached, the player with the highest score is crowned victor.

TARGET SCORE
Set a target score for players to reach. Once either player's score surpasses that target, the game ends and they are crowned victor. If both players surpass the target in the same round, players can vote to award the win to the player with the higher score, or play one additional "sudden death" round, with the higher scorer from that round winning.

When anything needs to be voted on, the game will decide at random which of the two votes wins.


FREESTYLE
Both players can pick whichever vehicle they see fit at the start of a round.

VOTE
Both players vote on the vehicle they would like to use for the round. The winning vehicle is assigned to both players.

RANDOM (FAIR)
A random vehicle is selected, then assigned to both players for the round. Certain vehicles, such as the Street Slicer, Mall Racer, Pink Lightning and Boss Throne will be exempt from the random selection, due to making a majority of gamemodes and levels too challenging to be competitive.

RANDOM (WILD)
Two separate vehicles are assigned to both players at random.

SHUFFLE OPTIONS
Three vehicles are selected at random from the list of vehicles. Then, each player can select which of those three they would prefer to use. This would keep an element of unpredictability and improvisation, while still allowing for some strategy and choice.


NONE
All obstacle spots remain in the default setup from that level.

GENTLEMEN'S RULES
Both players can enter the obstacle editor at any point, and select and edit an obstacle as they see fit. Only one player can select and edit a given obstacle at a time.

HALF EACH
If the level contains an odd number of obstacle hotspots, then this rule does not apply and the level remains in the default state. If the number is even, then half of the obstacle spots (selected at random) are assigned to either player, and can be adjusted by them from the obstacle editor.

RANDOM
The game will automatically generate a random obstacle for each hotspot, with the parameters (ramp length, boost duration, position etc.) of each remaining at the default values. Some obstacles, such as the Mega Wall and Ring of Fire will not be randomly selectable, if they don't mesh well with being placed suddenly in the road without prior build-up.

Whether or not replays get skipped is selectable, in case you want the ability to go back and capture a particular moment, or just want to keep the pace of the game up.


Both players can choose a face to use for their driver throughout the game. This is selected from Setup and cannot be adjusted mid-game (but passenger faces can). The neutral image of the face is used as the player's "profile picture", on votes, the scoreboard, and victory screens.

If no face is selected, the game just uses a portrait of Mr. Dismount.

At the start of a match, either player can set their own handicap anywhere between 100% and 1%. Once their score is calculated after a round, it's multiplied by this percentage before being added to their score counter. This can help even the scores if there's a large difference in proficiency between players, and ensure that both players are experiencing a comfortable amount of challenge.

Gamemodes are selected via vote at the start of each round.

A mockup of the potential gamemode selection UI


The original mode for the game. Both players score by damage done to their ragdolls and vehicle, with the round ending once both vehicles are immobilised or the round times out.
Players score exactly the number of points they obtained during the round, which is added to their scoreboard score.


A tried and tested classic. Compatible with most of the original Race levels.
Players compete to finish the target number of laps (likely lowered to 2?) as quickly as possible. If both players cross the finish line, the winner earns a number of points equal to the number of seconds ahead they were, multiplied by 65,000 (will need to be tuned). If either player is immobilised, the remaining racer automatically wins and earns 300,000 points (tune this; it needs to be a reward, but not enough to incentivise destroying your competitor.)


Why not?

Both players are placed in an arena, and tasked with immobilising their opponent. If both players are immobilised within 1 second of eachother, the round is deemed a tie. Once either vehicle is totaled, the remaining winner earns 500,000 additional points (tune). Both players also get to keep any points they scored from collisions during the round.

Derby levels would likely either be fully original, or altered versions of the boxing glove levels, minus the glove power-ups and with the police cars not activating until very late in to break ties.


A time-honored tradition. Car Chase levels are uniquely designed to be long, wide and winding roads with plenty of optional ramps and shortcuts around to keep things varied; a bit like Criss Cross with a bit of Thread the Needle thrown in. Traffic could be present on some levels, but only very few cars, travelling the same direction as the players, so as not to detract from the chase too much. Police cars could be present and will chase after whichever player triggers them, including the chaser!

At the start of the round, both players vote on their roles as the chaser or the runner. If the runner reaches the end of the level, the chaser's vehicle instantly shuts off and engages the brakes. The round ends and the runner scores a Nailed It! bonus, in addition to one Survival Bonus for any additional ragolls they can get safely to the finish. If the runner's car is totalled, the chaser wins and receives their own Nailed It! bonus. Both players get to keep any points they score from collisions during the round.

If any level has its own advanced scoring system, like Parkade Drift, then it's sorted into this category.

By the way, if Parkade Drift is ported into multiplayer, I'd suggest giving both players a separate floor to drift on, so they can get into the rhythm without worrying about hitting their competitor.

Once a gamemode is selected, both players vote for which level in that category they'd like to play by vote.

Players can make adjustments to their vehicle, passengers, faces, decals and obstacles just like in singleplayer before a dismount begins.

To prevent excess strain on the computer, both players are limited to no more than 4 ragdolls per vehicle, so that a maximum of 8 can be present at once, same as singleplayer.

Once either player is ready, they can press the Dismount button to ready, prompting a 50(tune)-second countdown to the dismount beginning. This helps alleviate players taking too long and frustrating their competitor, while allowing good sportsfolk to give their competitor all the time they need.

Once both players are ready (or the countdown times out), the players have five seconds to either choose racing controls or launch an automatic dismount with the button. Then, the dismount begins.

By the way, I think the music in Versus will be automatically set to Level Default, to keep the music varied without forcing players to manually change it, but Greatest Heights, Greatest Highs will play during menus due to its catchy listenability and being a rendition of the main theme. This applies unless music is set to None or Shuffle All when the game begins, in which case it stays as such. Players can still alter the music during the game from the pause menu.

A screenshot from Rolling Guy 0 was used to make the visual mock-up.