Okay, so I'm doing something either crafty or questionable: drawing the objects with Draw GUI.

It works, doesn't it?

Here. Just to give you an idea as to what I'm going for.

The character and GFX are temporary, but they help me realize what I want to do with the engine.

The floor's movement, being a view drawn onto a surface, is still one frame behind.

However, I figured it's more efficient to draw walls separately than to use blocks for indoor segments. They can stretch and keep doing the depth math accurately.

It took a while, but I got rotating flat sprites going.

Technically, it's a polygon, but it works.

If I were to do sprite-stacking, I have a basis, but my primary use for this is rotating attack animations.

...huh.

Didn't realize that debug mode was different on that version of Game Maker. Also shows WAY too much for players to use.

You can also click and drag some of those elements.

On the plus side, the tile layer ISN'T overlapping, and Draw draws objects.

On the other hand, NOW the tile layer lags during camera movement.

I guess I'd better let everything else lag for consistency (somehow), or fix the lag.

Dang it. I got the math right.

The real trick now is to optimize it. It's easier to do since it's technically all 2D.

The character and movement tests are going well, but...

OH. THAT's what Draw GUI does. It's not crunchy.

Then again, I thought that drawing a view to a surface would work the way I expected, but it ain't.

Part one of my zany scheme for a new project worked.

Using two Views, I can draw one squished, rotatable View as a texture, meaning I can use tiles for an isometric perspective.

Now, the tricky part is where everything looks like a pop-up book.

Two screenshots.