Well, so far, I've been testing, and have been exploring the world's outer reaches (even found
a multiple secret rooms), and have noticed a floating save point in the orange cave area by the beginning forest, on the left. Also, some of your corners and such don't match up, such as the bits of floating snow in the ice mountain area above the desert, and missing corner pixels in the place I call "hardcore caverns", the lava cave with the rock music. Other than that, this is AMAZING!
(Paint hasn't been cooperating, so no screenshots
)
TL;DR? This is good.