The composition is great. There's a lot of shading techniques on display, and it's used well without feeling like a mess. The extra background with the building in the first panel didn't need to be there, but you drew it anyway, showing that you're putting extra effort into this comic!
Did not notice the sound effect until author notes pointed it out. It's a nice touch.
I like the way you've depicted these characters and their travelling. One thing I would suggest however, is perhaps avoid using blurs for the sky in the backgrounds? It's a bit distracting given the flat colours you've otherwise been using. I see some good potential here anyway!