Alright... There's a lot wrong with this, and before I say anything, I want you to know what I'm about to say is called
criticism
Criticism is used to help improve peoples works, it may sound harsh,but I mean no offense to you, and you can improve using my
critique
Alright
I see 1x1 pixels, which isn't necessarily a bad thing, if they were
only 1x1 pixels, you could just resize them because SMBX's vanilla graphics use 2x2 pixels.
But the problem is, you're mixing 1x1 pixels and 2x2 pixels, which makes it harder to re-format to completely 2x2 pixels.
Another thing is, I'm see some weird masking on some of the sprites :
Be sure your first image (ex. npc-1) has a completely black background, and your "m" image (ex. npc-1m) has a completely white background, and the sprite itself is completely black.
The only thing I can say here that I haven't already said is, I would recommend adding some shading and outlining to the tent, and the pipe.
Your sprites look blurry, I would recommend getting proper sprites yourself by ripping them. (I would either play the rom on an emulator, use a screen capturing tool, and cut out the sprites, or use something sophisticated like ZSNES, which has the ability to turn off sprite layers, and take screen caps)
