Press [Esc] to display the main menu. Then,
enter one of the following codes to activate the corresponding
cheat function. A sound will confirm correct code entry. Press
[Esc] again to resume game play.

Code
Power and shields ahcrp
New item for hypercycle ahcre
500 photon, neutron and darts ahcrw
Gateways immediately open ahcro
Level select ahcrg<01-30>