Ok, I wrote some subroutines for the collisions. It works, but there are many bugs such as falling through floors or getting stuck in walls. Also the enemy seems to kill you immediately if you start moving as soon as the loop begins

There are also lots of other screw ups that show up occasionally. 

Thanks for the collision idea, leafy!

Thanks! And... What ropes?
(You mean how grappling hooks use rope?)

Use virtual pixel tests They function exactly like pixel tests, but return the solidity of a pixel instead of the color

So copy gdb to L1?

L1 is just the pointer to your tilemap data.  Replace L1 with the pointer to your tilemap data

Do I need masks if I only have a few triangle tiles that will be fully solid?

You only need masks if you want your tiles collision to be anything other than a square

I don't understand what N is for.

N signifies the number beyond which all tiles are solid.  For example if your first 3 tiles were scenery, and not solid, you would use 3 for N.  The routine tests for the tile number, and if it is greater than N, it considers the tile solid.  By ordering all of your tiles empty first, followed by solid, you can make this really easy.

Do X and Y need to be in r1 and r2?

r1 and r2 are the X and Y onscreen coordinates, measured in pixels from the top left corner of the tilemap.  If your coordinates are inflated, you don't want to use the inflated version, but first de-inflate them to get the onscreen pixel coordinates.

W is tilemap width (in tiles) right?

Yes

You don't need to use L1, as I was saying replace L1 with the pointer to your tilemap data.  You could replace L1 with Str01 if that was where your tilemap data was stored.

And if the only empty tile is 0, you would want to check if the tile number is greater than zero if you were checking for a solid tile. 

Like I said, if the only empty tile is tile#0, you would want to check if the tile number is greater than zero to detect a solid tile

If L1 points to your map data, then yes

I did it, but it fails <.<

It gets frozen and I have to pull a battery.

Methinks the while statement screwed up and won't ever be false, causing infinite loop.

But however, the tilemap should show up if everything else does...

Actually, it never should virtual pxltest until the player moves.
The only one that works when the player is moving still uses the regular pxl-test (which I forgot to change) and it used to work.