Solving $N$-player general sum matrix games is known to be PPAD-complete, and even for two players algorithms such as Lemke-Howson can take exponential time in the worst case. On the other hand, verifying that a solution is indeed a Nash equilibrium can be done in polynomial time.
Are there standard examples/benchmarks/libraries of bimatrix or $N$-player games that
- are relevant for applications or concrete problems (i.e., are not just synthetic numerical examples), and
- ideally have not been solved yet, or can not be solved without significant computational effort with current methods?