Mega Man Battle Network 1
From The Rockman EXE Zone Wiki
Mega Man Battle Network is the starting game of the Mega Man Battle Network series and its alternate Mega Man timeline, that emphasized on the evolution of computers and networks instead of the original's emphasis on robotics.
The game was ported to the DS with modified game mechanics and extras involving Mega Man Star Force characters in Japanese-only Rockman EXE Operate Shooting Star. Its extra mode, Rockman Star Colosseum, is a fleshed out mini-game that entirely takes place in the game's overworld setting.