Very cool game and quite sophisticated for a jam. I am missing some level selection because I got stuck in level 3, like 2-3 times, and had to restart the whole game.
For some reason, the first time I got to level 3, I wasn’t able to build anything. The second time I got to level 3, I was able to build, so I outlined an initial shape of my roller coaster first, but one of the red points got created inside of the already existing (initial) track, and I was unable to interact with it (could not move it or delete it). Therefore, I was stuck and could not progress. After pressing the bin button, my build got deleted (as I was expecting), but then I was unable to start building again, so I had to restart the game once more.