Hamtaro: Ham-Hams Unite! (とっとこハム太郎2 ハムちゃんず大集合でちゅ Tottoko Hamutarou 2 - Hamu-chanzu Daishuugou Dechu) is a Hamtaro adventure video game developed by Pax Softnica and published by Nintendo for the Game Boy Color handheld video game console.
The player (Hamtaro) is controlled by the D-pad, and holding down the B button allows the player to run. Pressing A will open a dialogue box with different Ham-chat words depending on context. For instance, standing next to a sunflower seed and selecting "hif-hif" will pick up the seed, while standing next to an NPC and selecting "Hamha" will open a dialogue with the character. Different options will yield different outcomes, rolling (Tack-Q) into NPCs will usually elicit a negative response. Objects in the world can be interacted with, like climbing trees and pulling drawers open.