Visually, Network Transmission is rather impressive, but in the subtlest of ways. This is a game that screenshots do no justice for. The animations are smooth and transition rather well. In fact, the only real negative I saw was the 'linebacker' position Mega Man adopts when running and resting. But, this is only a personal thing and shouldn't count against the game. The various animations for the different enemies and Net Navis you run across are also nice to see. At face value, the cel-shaded graphics do come off as a tad hokey, if not bad. I've even heard some people refer to the look as SNES era graphics. This is clearly not the case. While not the most impressive graphics I've seen, the package is still solid, especially when lighting effects begin to come into play.
Your like or dislike of the game's sound will come down to one thing -- your tolerance of the Japanese language (or rather, the squeakingly annoying actors that are usually cast as voices). All of the voice work in Network Transmission is in its original Japanese form (with English subtitles), so take that for what you will. The sound effects and music are very well done, and reminiscent of the GBA series of games it's based after.