Press 1 5 0 when choosing a pilot,to get 11 powers and 9 lives.
A "Magic Key" cheat menu can be activated where you can change the starting stage, number of ships, etc. Once activated there will be a new option on the title screen, telling you to press the GRAPH key to go to the MAGIC KEY menu.
Activation of the cheat menu however is a bit tricky, as it requires keeping both the UP and DOWN directions pressed on a joystick inserted in port 2, while starting the game. Something not possible with a regular joystick.
For the openMSX and BlueMSX emulators, however this can me emulated as both have support for a MagicKey dongle to activate this cheat.