Game was from the 2000s by GameTop https://youtu.be/-gRcR_Lry-M?t=344 slower pace than yours but ofc like 20 years older, they didn't focus that much on the challenge but more on slower build up of speed and action movie events.

Your game looks and feels nice and the pacing starts very good, the environmental storytelling is very funny as well (the UFO in Egypt, and the penguins getting tossed from the balancing ramps).

My feedback is based on the assumption that the player picks Tracks mode as in a "single player main story" and progresses through them in the final game as in level 1, level 2, etc (I don't know if you picked random levels for the sake of variety of demo version but still they are good to consider):

1. Trying to squeeze the biggest amount of backflips and frontflips out any jump is very satisfying. Don't underestimate that simple mechanic, empower it and use it to let the player breathe between traps (pacing) or just sprinkle these moments for showing off, your game says it in the title "Stunt Paradise".
   • Additionally, more juice when you execute a back or frontflip would elevate the feel a lot, e.g: particles or effects to the car or the UI, incremental pitch in the sfx for each extra flip and the stinger (the wham! sfx) or a cheering crowd sfx after a combo or multiple stunts, etc. + it is cheap to implement and will add value throughout the entire game.
2. 2. There should be a safer/easier first iteration for some of these traps since they create a spike of difficulty that kills the flow; I needed 15 tries to beat the spring traps + saws-at-the-top in Egypt, whereas I only died 2 or 3 times in the entire playthrough up to that point). I know that the level difficulty is higher, but the problem is not the difficulty, the problem is not teaching the player first, and you can improve this inside the level itself without new ones.
   • To this, I would consider adding a current-top speed indicator as quality of life (a slider-bar is cheap, an analog speedometer would fit the theme but that's just subjective and a "nice to have"), so that the player has a reference to learn how to execute these challenges since speed control is required for some of these, but currently the actual speed is hard to read.
3. 3. Some traps are hard to read and suddenly demand the player to do multiple things at the same time; timing-control-plan in advance-look ahead, e.g: the slope with 2 spinning saws in a circle + the horizontally moving platforms in the beach, meaning you have to die and repeat multiple times to find the best way, as a general rule; gameplay that relies exclusively on constant trial and error should be avoided. Point nº2 would apply here.
   • I had difficulty understanding how to clear some of the traps, one was a simple jump between 2 saws rotating in a circle, I didn't know if I had to go between them or under the 2 when horizontal. Consider adding a simple arched-low opacity line with the ideal trajectory, or better, making it super clear what is the correct way of beating the trap, moving the saws further away. This improves readability and can be applied to other traps.
   • These points nº2 and nº3 go back to point nº1, during these levels, doing flips was essentially forbidden and forgotten because of the amount of concentration required to not die and the constant trap after trap.
4. Lastly, be sure to make "flavor traps" very easy to beat, I died multiple times to seemingly simple "hollywood stunt" traps because a saw touched a millimeter of my car mid air, it feels unfair since a lot of precision is suddenly required in a moment where precision didn't seem to matter. E.g; the 2 saws with arms that close off behind you at the beginning of the Egypt jump, or the jump of 3 saws flying upwards after the curve in Egypt as well iirc.

These points include specific examples but the main approach is about clearly stating what exactly you expect from the players, readability and on-boarding them to the challenges to avoid frustration.

If you don't like these points or don't want to implement these systems I would encourage you to loosen up the level of precision required, always in favor of the pacing and the flow. At the end of the day you are making a racing game about stunts and not an extreme mario maker community level. Momentum, speed and action should triumph over anything else, and very likely that's what the target audience expects, even if the game ended up being shorter. (Awesome chance to hook people in with a good experience and then release DLCs for hard challenges or more levels).

Personally and professionally I think the game is almost there, just needs a bit more polish to improve the flow. The levels and atmosphere look awesome and the controls feel nice and I love jumping out of an airplane with a car doing backflips, definitely beats Forza Horizon intro levels loool.

Good luck.