- Bonus weapons
Successfully complete either game with the indicated character to unlock the corresponding weapon. Notice: Pete, Gourmand, Julia, and Accel do not unlock items in the first Power Stone.

Turbo Helmet	Pete
Amenomurakuno	Ryoma
Totem Hammer	Galuda
Giant Boots	Gunrock
Crystal Ball	Rouge
Maches Chainsaw	Jack
Twin Potion	Wang-Tang
Stone Sweeper	Julia
Decoy Bomb	Ayame
Soccer Ball	Falcon
Thunderbolt Rider	Accel
Wok Gun	Gourmand

- Play as Pride and Kraken in Power Stone 2
Successfully complete 1-On-3 mode with Falcon in Power Stone 2 to unlock Pride and Kraken.

- Gunrock's Slot mini-game
Get 1,000 medals in a mini-game to unlock the Gunrock's Slot mini-game.

- Play as Julia in Power Stone
Successfully complete the original Power Stone with Pete to unlock Julia.

- Play as Pete in Power Stone
Successfully complete the original Power Stone to unlock Pete.

- Play as Mel in Power Stone 2
Successfully complete 1-On-3 mode with Pride in Power Stone 2 to unlock Mel.

- Play as Final Form Valgas in Power Stone
Successfully complete the original Power Stone with Valgas to unlock Final Form Valgas.

- Play as Gourmond in Power Stone
Successfully complete the original Power Stone with Julia to unlock Gourmond.

- Play as Valgas in Power Stone 2
Successfully complete 1-On-3 mode with Kraken in Power Stone 2 to unlock Valgas.

- Ayame's Shuriken mini-game
Get 500 medals in a mini-game to unlock the Ayame's Shuriken mini-game.

- Play as Valgas in Power Stone
Successfully complete the original Power Stone with Kraken to unlock Valgas.

- Play as Accel in Power Stone
Successfully complete the original Power Stone with Gourmond to unlock Accel.

- Play as Kraken in Power Stone
Successfully complete the original Power Stone with all characters to unlock Kraken.

- Bonus weapons in Power Stone
Successfully complete the original Power Stone to unlock the following weapons: Machine Gun, Nyoi-Bo, Power Shield, and Ray Gun.