I don't know much about Mega Man Battle Network and I know even less about .hack lol.
The story isn't super gripping... at the start it's just "let's go get some data" "ok" without any explanation of how these two universes are crossing over. Some of the dialogue could have been proofread, and instructions on where to go aren't always clear.
Visually, it looks pretty good, and the audio is nice too (though I'm not sure about the music changes whenever you start a boss fight, it's a little awkward).
And the gameplay is fine, though the battles are a bit repetitive.