Wow thank you for the long review and all the compliments! I'm glad you noticed the different background, I had fun making them to add a subtle little visual variety.
I agree with you that using bombs as a protection was a bit underused, and could be expanded. I initially wanted to make it the focus of the game, since unlike Bomberman there's no chain reaction so bombs can be both a protection and a treat. But in the end I just had too much fun making the other mechanics so I made more levels with them.
Thanks for playing through the end despite the difficulty!