Mega Man: Network Transmission takes place after the first Battle Network title but before the second. A month after Lan and Mega Man thwarted the evil takeover attempts of the WWW organization, a new "Zero virus" has spread into cyberspace.

Mega Man: Network Transmission is based on the GBA Battle Network series. Mega Man doesn't attack using his trusty blaster but with a set of battle chips that can be switched on the fly. Each battle chip hones a different weapon attack such as a cannon blast, a sword slash, or a bomb. MMNT takes the concept and puts it in a side-scrolling action title.

Players start off in Lan's house, similar to the Battle Network series. Here Lan can check his email, check his battle chips, and save game status. Once you ready to start up a level, simply head to your Net Navi and log in at any available station.

Players will be able to stock five battle chip attacks at one time. Mega Man can change his entire set up of chips after a meter refills on-screen. Battle chips can be chosen on the fly via the R and L triggers. The battle chip that is currently armed is indicated at the top and bottom of the screen. The problem is you have to constantly check to see which one you have armed and it takes your concentration away from attacking enemies. It would be much better if an icon flashed near Mega Man to give some sort of visual indication of which battle chip was armed to smoothen the flow of the game.

Another problem is that network Mega Man is far less agile. Not only is your buster gun completely useless against enemies, but Mega Man runs slow and can be attacked by his more advanced enemies simply because he doesn't have a control range to do much. The boss battles are all the more difficult because switching battle chips on top of trying to dodge enemy attacks with the blue bomber's limited movement is tough beyond belief. Also, because battle chips are given to you at random, you may wind up with chips you just don’t need, then wait another 30 + seconds to try again.

On a high note, the mix of cel-shaded characters and colorful 3D backgrounds make MMNT an attractive game. The electronic lines that decorate blocks or fire embers that glow add to flair of the title. The cinemas look fantastic and use cel-shaded visuals at 60fps to show off some awesome battle animation. The blasts and other sounds are standard Mega Man, nothing too fancy. And if you like hearing Mega Man speak Japanese, well, he does in this game.

Mega Man: Network Transmission is an idea that didn't pan out right. The battle chips work well in Battle Network because of its grid-based action. But in a side-scroller, the fast pace action doesn't accommodate players that need to constantly switch and check what kind of battle chips they have and how many shots they have left. Save the battle chips for Game Boy and bring back the action–based Mega Man in the next game.