the game is unplayable for me - the races seem to end like 8 seconds in randomly, i think you should turn off ending the race if the other racers die (from comments that seems to be what's happening - can add respawn for them or something or just turn off ending race when that happens?)
and don't worry about the game jam thing preventing you from updating this that's silly, game jams are designed for you to put heads together and create cool stuff - that's their core objective. you can still update the game if you want, i think this is a scenario in which it's worth adding fixes and you can always just say 'originally made for game jam ____')
EDIT: i think this miiiight be because of varying frame rates on different computers? could try making racer speeds frame rate independent, might fix the problem if that's the core cause. couldn't say for sure but that may be why for some people in the comments this doesn't seem to be an issue.