Dillon's Rolling Western
This game is titled Dillon's Rolling Western in North America, Europe, and Australia, and The Rolling Western in Japan.
Complete Stage 3 Day 1 to get the Ancient Buckle. This item enables Arma-mode, which allows Dillon to become invincible and do triple damage to enemies.
Sal's Hut map location
Successfully complete and earn all 50 Stars. You can see 3D models of all the Grocks at this location.
The Old Mission map location
Successfully complete the game and have at least $100,000 in savings. You can fight a hidden Boss at this location.
Strategy guides from GameFAQs