Wow this is a very ambitious game for a game jam, but I am impressed with what you were able to put together. Unfortunately I struggled quite a bit to put a vehicle together. It looks like there were either some glitches or it is not as straight forward as I have expected it. Performance for such games in the web is always a bit an issue, especially for people without a gaming PC. Maybe a release as a standalone game is better suited.
Congratulations to this very ambitious game and I think you have already a good start for a fun game.