This video shows me defeating every Boss and getting all five Gold Cards from each of them.

Bosses Beaten

Sirius (Hostile) Green Gardens 2
Winged Beast Green Gardens 4
Artemis Blue Resort 2
Sewer Savage Blue Resort 4
Orion Red Mountain 2
Hot Avenger Red Mountain 4
Regulus White Glacier 2
Cold Killers White Glacier 4
High Tech Harvester Black Fortress 2
Altair Black Fortress 4
Spellmaker Rainbow Palace 2
Sirius Rainbow Palace 4