I’m not sure if it counts as a bug if it’s technically unfinished/missing a feature haha. The plane has a constant thrust which increases/decreases based on the pitch (fastest speed is straight ahead) because this uses a curve it was easier to slow the plane down over time by adding a negative force every second so eventually the negative force becomes much greater than the force applied in the forward direction. When you hit a swirly it resets the negative force back to 0 and applies a speed boost for like 3 seconds. I tried playing with a setting that recorded speed and would restart the level if it went below 0 but it causes some weird issues if you accidentally clipped a building so in the end I decided to just leave it in and let the player decide when it was time to restart. thank you for playing!