Okay, I am debating using half-byte tilemapping or full byte. Full byte will be more a problem but can allow for a much larger tileset ,which is generally a good thing with platformers. Half-byte will be slightly slower but easier to handle with free RAM and will allow for larger maps.
Which should I go with?

What's the largest square tilemap that L1 could support in full-byte? Would it be floor(sqrt(768))? Or whatever bytes L1 has?

Hm, maybe I will use the front buffer, just because it's so convenient xD
and fast, too.
@Squidgetx How do you account for when the pixels are off the screen? You use a for loop for hit detection, but what if the pixels aren't on the screen when the for loop reaches it, or do you just set a terminal velocity?
EDIT: Oh wait, I get it.
EDIT2: I'll use the tile detection method from Graviter but the tilemapper from squidgetx's sand land, I guess.

Aw right, I got it working. Time to get walljumping in, then moving to specialized tiles!

Cool, can't wait to see what this looks like
So, just to clarify, it's a smoothscrolling physics platformer?

So, wall jumping is like bouncing off the wall, or the ability to jump back and forth up a pair of parallel walls?

Sounds like you're making some pretty cool progress on this game. I can't wait to see a screenie of it.

I just want to get this clear. So, The Slime is just the name of your character in an adventure platformer? That's totally okay if it is, but I clicked on the forum thinking you were making a game with a fluid, ameoba-like slime in a platform game. That would be a cool project for someone to make.