A racing game with mechanics similar to the building system of fortnight where you can build ramps or set traps as you race maybe placing a ramp in front of your opponent to make them crash into a wall or placing one for yourself to clear an obstacle or reach a shortcut. It would be set in semi open maps to where no race is usually played the same way based on what powerups you get.

It would work by assigning a simple trigger based build system with L and R to turn left or right and the right stick to place pieces where you want them, it may feel funny at first but I think it could work.

Powerups: Kicker ramp Turbo ramp Oil pool Pitfall Wall Instant respawn shield (as long as you're glowing if you would die you warp back to the map with a speed boost to get you back in the race) Perhaps more

Setting: could be all sorts of things but personally, I'd like a fantastical world with Insane tracks with the endgame being tracks that you race through like warped space and time. Colorful , contrasting, not realistic at all. Of course this is just polish and could be just as fun in a less intensive setting.

Have very long open tracks that give a real sense of speed without a loss of control.

Customizable vehicles with a special trait to each of them, weight being an important factor for things like armor vs lightweight jumping types, could also be cool but is not necessary to the core concept.

Wouldn't have to be graphically intense and a prototype could be drawn up fairly quickly Anyways that's my idea.