Hello Raotheron, thank you for your valuable feedback, it means a lot.
I knew that the terrain was not rendered under some conditions (as far as I saw, there isn't such an issue in the downloadable desktop version, but I could be wrong here). However I don't really work on this game anymore as I am currently busy with school.
I was not satisfied with the vehicle physics in this project so I planned and started working on a new project with my own vehicle physics and bigger ambitions, but as I mentioned earlier, I don't have much time currently. Hopefully I will get to a decent prototype by the end of the summer vacation and if so I will upload it as a separate project here on itch.io.