Control hints, and new control scheme

New version!

I’ve updated the control scheme to be simpler, use up less buttons and modified the mouse control rect to scale according to the game window size. I’ve also added a race course made up of checkpoints. (no proper start/finish yet) If you follow this course, it will show most of the game’s controls via control hints, as a sort of tutorial. Besides just updating the control scheme I’ve also made some minor changes to the looks of the game, and added a “ground” control mode, which only powers the wheels of the craft.