I did some in-game testing in RPG Maker VX Ace of a style of oblique projection that Ultima VII and Ultima Online used. You can see what it looks like here:
And while this perspective looks great, there are some problems. Watch the following movie clip to see how there are clipping issues when the minifigure passes in front of and behind the orange block representing a building. Especially take note of when the character passes around corners, or moves inside and outside of shadows.
The technique makes use of two picture layers - a top and a bottom - as well as a middle layer for game characters. Here is the bottom (parallax) layer:
Here is the top layer:
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Does anyone have any ideas on making this work?