Thanks a lot for this well-thought feedback! As said on other comments, we are planning to continue working on it, we have another version coming up soon that is going to address some bugs and some problem with the movement of the ship.
We have some planning on working on different levels, with different atmosphere, enemies, challenges, etc... Also different ideas on how to add incentive on getting off the train, change the coach you're attached to, etc...
We know sometimes it can be hard to follow up on where enemies are, especially when they're behind you, that is something we're not addressing in our next version since it's a bit more complicated to approach.
As you said we wanted for the game jam to be doable and not have a hard challenge, it was supposed to get the idea of the game and what it could do first. We will address the balance of it in future release.
Thanks again for your time and feedback :)