Hint: Giga Charger
The Giga Charger is in the basement. Use chibi-vision to look up at the ceiling keep looking until you spot it. Once you do, shoot down the wooden board nearby and follow that path. Once you obtain it, Captian Plankbeard will tell you about the Giga Robos leg.
Hint: Frog Forking
Have you been curious about those weird looking rings that have a frog's head on them? Well, collect them! If you give each one to Jenny (ten in all) she'll take that stupid frog hat off.