Just beat the tutorial, haven't tried wi-fi yet. If your only attraction to this is out of love for the DQ license, you might want to reconsider. It's a good game, but it plays like a strategic board game, your units just happen to be DQ monsters.
That said, it's one of the best things on DSiWare and it a lot of fun. I spent my other 500 points on PiCTOBiTS so I'm in DSi heaven.