Successfully complete story mode. The title screen will now feature either Geo and Omega-Xis. Shidou will now say "Shooting Star Rockman 3" instead of "Ryuusei no Rockman 3".

Complete the indicated task with a special wireless transmission to have the corresponding silver star appear at the title screen.

AA/GJ Star: Defeat Acid Ace BB or Grave Joker RR.
Mu Star: Defeat Burai ZZ.
Sigma Star: Defeat Moon Disaster Sigma, Apollo Flame Sigma, and Sirius Sigma.

Complete the indicated task to have the corresponding golden star appear at the title screen. After unlocking all five stars you can challenge Crimson Dragon SP.

Black Ace Star: Complete the game.
G Comp Star: Collect all the Giga cards.
M Comp Star: Collect all the Mega cards.
S Comp Star: Collect all the Standard cards.
SS Star: Defeat Sirius.