The tell-tale sign for NP, but not P problems is that they
need a lot of running time, but not a lot of memory (for
some value of "a lot"). NP problems, including the NP-complete
problems are still solvable in polynomial space. That is,
they are in P-SPACE.
So, I'm very curious what makes you think hardly defined
problem seems to be NP-Complete.
Abigail