Unlockable: Trauma Suit
Let Chibi Robo completely run out of energy at least once. Telly Vision will rescue you and you will receive the "Trauma Suit" which consists mainly of bandages and a very funny pose animation. After this, you can equip and unequip the Trauma Suit anytime from your items page.

Unlockable Tao Suit
Clear Free Ranger 6 training course to unlock the Tao/dog suit.

Well, the hint is one detail short for it to work. There are only five Free Ranger Missions. There is something you have to have first. In the kitchen, Tao's dog house has "Dog Tags" (like military and Navy tags) that belong to a missing Free Ranger. Before the final mission talk to Sarge until he mentions the Tags. Then you have the Tao suit. (Unverified)

Submitted by Canca boodeewoowoo
Addition by OnyxAlien Snakefreak

Unlockable Frog Suit
Get the squirter on the table in Jenny's room and fill it. Hose the frog in the backyard several times and it will award you with this suit.

Unlock Ghost Suit
This can only be found once you've acquired the Trauma Suit. Strike a pose in the Trauma Suit and you'll go to the Chibi-House. When you wake up there, you'll be wearing the Ghost Suit.

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.

Easter Egg
You can meet aliens if you have the chibi radar. You go to the backyard and pick all the weeds. After you do this you take out the chibi radar and stand in the middle and activate the radar. Then aliens will slowy fall out of the sky.