Changes

You move on the horizontal plan with only 4 directions (X and or Z axis), and you can jump (Y axis) to get some platformer gameplay. You can't actually move in diagonals on the horizontal plane (X+Z movement)

The backgrounds elements are in "3D but " (isometric oriented) and you can't use the Y (3D vertical ) axis, therefore you can move on the horizontal plane (X/Z) in 8 directiondirections.

But this This leads to a strange and odd impression sensation as the levels are designed in "diagonals " on screen but the player would instinctively move mostly in up/down/left/right 2D fashion(X+Z axis at the same time).