An option that print the depency graph (similarly to make -p but like pstree) in a structured way will make it very easy to see the project structure.
The possibility to specify the depth and see if it had been truncated are maybe a good idea.

from make info page:

"GNU `make' does its work in two distinct phases.  During the first
phase it reads all the makefiles, included makefiles, etc. and
internalizes all the variables and their values, implicit and explicit
rules, and constructs a dependency graph of all the targets and their:"