Here is the full list of all 20 Jet Car Stunts achievements worth 200 gamerscore.
Complete all the levels in "Original - Platforming - Easy" with at least a bronze medal.
Completed all the levels in "Original - Platforming - Hard" with at least a silver medal.
Completed all the levels in "Original - Platforming - Impossible" with at least a gold medal.
Completed all the levels in "Original - Time Trial - Easy" with at least a bronze medal.
Complete all the levels in "Original - Time Trial - Intermediate" with at least a silver medal.
Complete all the levels in "Original - Time Trial - Hard" with at least a gold medal.
Complete all the levels in "Bonus - Easy" with at least a bronze medal.
Complete all the levels in "Bonus - Hard" with at least a silver medal.
Complete all the levels in "Bonus - Impossible" with at least a gold medal.
Complete all the levels in "Freestyle - Easy" with at least a bronze medal.
Completed all the levels in "Freestyle - Intermediate" with at least a silver medal.
Complete all the levels in "Freestyle - Hard" with at least a gold medal.
Complete all the levels in "Free - Platforming" with at least a gold medal.
Complete all the levels in "Free - Time Trial" with at least a gold medal.
Complete all the tutorials.
In mid air flight, barrel roll the car two times or more.
In mid air flight, back flip car two times or more.
Spin the car 720 degrees or more whilst in mid air.
Successfully land the car after a massive jump.
Drive the car at super high speeds.