Notice that x and y are proportionally equal and perpendicular to your line of sight, but z is not. It's not 30-90-30 isometric. Also z should actually be pointing right at you rather than down and to the left if this was true 3D rendering. Hence this is a style. Does it have a name?
Note: z is free to scale any way you like so this style can be made into a kind of isometric. That is x, y and z can all have the same scale. But regardless of that does this have a name that wont be confused with 30-90-30 isometric?