The captive invader robot : You will have to enter the dungeon twice, once from the castle library and once from the underground tunnel (Mordred's laboratory).
(see the related questions)
Mordred's robot warrior: As Merlin the owl, Dodge the projectiles and swoop down to the bombs, avoiding the spinning blades, and drop the bomb on the robot when it blinks red. As your player, duck down until the robot is directly over you, then jump onto the robot, then the pedestal, then the chandelier. Mordred will then shoot a laser causing the chandelier to break and hit him. Repeat this with other chandelier. (there are two chandeliers)
(see the related question)
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.
There is no jail on Astro Knights Island. There is a castle dungeon, where an attacking alien robot is being held after his capture. (see the related question)
Actually, Merlin has little to do on Astro Knights Island. He recovers the fuel rod from the dungeon when the robot self-destructs. And he battles Mordred at the very end of the island.
you fight the robot on jungle planet
One of the robot attackers was captured and put in the castle dungeon.
You do not get or use a bucket on Astro Knights Island.
There is no treasure chest on Astro Knights Island.
Things that Zap you on Poptropica : Lasers (Spy Island) Electrified Windows (Spy Island) Mini-Bots (Spy Island) Electric Fence (Diamond Mine, Nabooti Island) Electric Caterpillars (Jungle Planet, Astro Knights Island) Mordred's Robot (Astro Knights Island)
Throw the switch when you get the cheese. You can enter the dungeon from Mordred's underground laboratory once you have the robot owl. (see the related question)
When you awaken the robot owl Merlin, he flies out of Mordred's lab. In order to get him back, you have to feed him the robot mouse. (chomp)
There are no bird eggs in astro knights island.
Feed the robot mouse to the owl, and then he will follow you. In the dungeon cell, click the owl, then the fuel rod, and he will retrieve it for you. (see related question)