Level passwords:
Enter these codes at the password screen to access the corresponding levels. The code symbols are Greek, but here is information on how they can be identified:

Delta - triangle
Phi - shaped like an oval intersected by a vertical line
Sigma - appears like the letter ''E''
Psi - trident-shaped symbol
Omega - looks like a set of earphones

Phi, Sigma, Psi, Omega - Nepal (easy)
Omega, Delta, Sigma, Phi - Cairo (easy)
Psi, Sigma, Sigma, Phi - Island (easy)
Delta, Phi, Delta, Omega - Shanghai (easy)
Delta, Phi, Omega, Sigma - Village (easy)
Phi, Delta, Phi, Psi - Pankot Palace (easy)
Phi, Omega, Psi, Omega - Venice (easy)
Delta, Psi, Phi, Omega - Salzburg (easy)
Sigma, Omega, Delta, Sigma - Berlin (easy)
Phi, Psi, Delta, Phi - Alexandretta (easy)
Phi, Omega, Omega, Sigma - Nepal (hard)
Phi, Phi, Omega, Psi - Cairo (hard)
Omega, Delta, Omega, Psi - Island (hard)
Omega, Delta, Phi, Psi - Shanghai (hard)
Sigma, Phi, Omega, Sigma - Village (hard)
Omega, Psi, Psi, Omega - Pankot Palace (hard)
Omega, Omega, Delta, Phi - Venice (hard)
Psi, Delta, Sigma, Sigma - Salzburg (hard)
Psi, Omega, Delta, Sigma - Berlin (hard)
Psi, Psi, Phi, Omega - Alexandretta (hard)
Delta, Psi, Delta, Sigma - Nepal (Normal)
Sigma, Delta, Sigma, Psi - Cairo (Normal)
Sigma, Omega, Psi, Psi - Island (Normal)
Sigma, Psi, Psi, Phi - Shanghai (Normal)
Sigma, Psi, Omega, Phi - Pankot Palace (Normal)
Phi, Delta, Psi, Sigma - Venice (Normal)
Phi, Psi, Delta, Omega - Salzburg (Normal)
Phi, Delta, Delta, Sigma - Berlin (Normal)
Phi, Psi, Phi, Sigma - Alexandretta (Normal)
Sigma, Phi, Delta, Omega - Village (normal)