Tip: Make sure that ALL exit-enabled pipes, doors, etc. have a screen exit defined, or they'll take you to Level 0, the "endless" bonus game. Unless Start+Select is enabled, the only way out of it is to reset the game.
I'm rejecting these graphics, not because of their usability, but because they could have been bundled in one file.
Since it's the same background, but with only different colors, I recommend you rerip it to use both palettes. Make sure to distinguish both folders, like "Mountains (Day)" and "Mountains (Sunset)". The night version was fine because it had stars. Once you combine these two palettes for this same background, I can accept your submission.