AMEND: THIS DOESN'T SEEM TO WORK AT ALL.

Check this out for a NONWORKING example of a shader, heheh.
I thought it was sahding correctly, but it's just due to sprite flipping
that that looks like the case. It's definitely not shading correctly,
and the lighting is obviously fucked in other regards by these changes.
Pushing because I'm working on other stuff for a while

The remainder of this messages is inaccurate.

Okay. This is kind of a shitty test but bear with me here.

Menu is messed up due to enabling lighting.

in game, screen is entirely dark except for Red's NS#0 sprite. But try moving the sprite to the left or right corner. The lighting definitely does change, as you would expect it to.