Very impressive! You created a whole little world, and I liked the little touches like exiting the vehicle by clicking on the door. Keeps you immersed
I was able to tune to the 2nd frequency, and I understood that I need to track the signal with the device in the car - but I couldn't find it - it lead me to some wall, and when I exited the car it kicked me to the elevator, I assume because I was on the darkness for too long. Honestly the first frequency, I just followed the road, and didn't use the device.
Small things I see that can be improved - subtitles (I appriciated that fact you wrote the frequency above the machine - but it could be nice if I can see it when I tinker with it), sound balance (sounds/music was too loud sometimes), and maybe tutorial for slow people like me :)
Great job!