I got it through Gamefly and pretty much had to force myself to finish it. The whole game felt like it was carelessly rushed to meet a deadline. It seems like every time I started to get into it, I'd run into yet another poorly explained challenge or boss fight that would hold me up and annoy the hell out of me. And the controls drove me crazy. Seemed like no matter what set-up I tried it was flawed. The cursor only moves within a small box within the screen making it easy to lose track of, and on the nunchuck set-up the stick seemed oddly unresponsive. Then there's an annoying camera you have almost no control over.
I never tried any of the multiplayer aspects though other than the garden, so I can't comment on that. For the record I've never played the original Nights. I did love Sonic and the Secret Rings though after you suffer through the first few hours to get Sonic up to where he should have started at.
It have to be in the $10-$15 area before I'd personally consider buying it.