None of the planets the knights are on. But you still have to defeat all three planets, and the knights will go with you. After you find and help all of them, they will tell you to go find an asteroid where the princess is supposedly kept. The coordinates are X-11 Y-82.
She isn't on a planet.she is on a asteroid (if you are talking about astro-knights island)
With Mordred
Astro Knights
I think that it was Mordred.
The phoenix is on the jungle planet
The Princess has been captured before the start of the quest on Astro Knights island, and is not seen until the final battle in the lair of the Binary Bard.
she is on astro knights iland in space
the jungle planet is in space on astro knights island.
Green.
There are no cubes on Astro Knights island. There are ice floes on the Ice Planet, that you jump across to avoid the robot fish.
The Laser Lance.
No. Although there is a red planet, it is the Fire Planet and is not intended to be Mars.