I'm honored to be reviewed by Chew Chew Train developer (BTW amazing game), thanks for your feedback, I know there lot of things that could be done in a better way, or at least get polished a little bit more, but thanks for your feedback!
I'll try to make some updates in a near future, for sure I'll add some indications during the level, lot of people said about this point.
Again, thanks for your time and you did an amazing game with Chew Chew Train, congrats!