Cool game :)
Leaderboard should show only your PB I think, otherwise 1 player can fully fill it.
And there is a bug, that if on death you go to the main menu and then back to the game, then you will respawn and your score and level won't reset.
Viewing post in Mad Rush jam comments
Created issue for leaderboard item. Need to touch base with Silverwolf on that one : https://github.com/finalsabbath/3d-runner/issues/1