The gradient vector of a function is perpendicular to its contour lines. At a saddle point, two contour lines cross and the gradient vector must be perpendicular to both these lines at the crossing point. Although it is true that some pair of contour lines will cross at a saddle point, Maple will not always choose to draw exactly that pair of lines. Below is a contour plot of the function g in which the crossing contour lines are not shown. There is still a cross shape at the center of the region, which is enough to identify the saddle point.
More exotic functions can have more than one critical point.
The function h defined below has two maxima, a minimum, and two saddle points. Label each point as a maximum, a minimum, or a saddle point. Give approximate coordinates for each critical point. You should zoom in and zoom out on each graph to be sure you have found all the critical points. However, functions of multiple variables can and do behave in strange ways.