Thank you very much for the feedback and for the kind words!
For the death under the narrow tunnels, like for any other mechanic in the game actually, I went for a "discover it yourself" approach, meaning once you know you die under a certain tunnel, then you are likely not going to try it again (unless you misclick of course). I could't find a better way of communicating that, but I tried to make the player discover that as soon as possible with early levels, so you don't end discovering it later on and lose progress on a more complex level like the ones in the second half of the game.
Unfortunately, I tried to download and play your game to provide some feedback, but got stuck on the car selection screen sicne I don't have someone to play with at the momennt...
The graphics and polish, for what I could see, are very nice though :D