Amazing.
At first I thought it was so simple and wouldn't cointain any challenge, but the progression is well made and the music just sets the mood perfectly.
Characters are distinguishable enough in art and mechanics.
The train outlines don't really match the rest of the scenario, and some hitboxes could improve.
The bridge is kind of small for a first level maybe, but defenetively has a lot of potenial if you change the shape, blend it, or have more bidges but smaller... it's main part for making a lot of levels or even difficulties for those levels with minimal changes