Game wasn't very great in the end (it's just okay), and not near up to par with the real Wario Lands. I'd kill to get a Sakamoto/SPD1 made Wario Land 5.

how is 850k poor sales?

This isn't true.  A platformer where you swing the controller to jump is not better..

I think that I might agree with you being better than Super Mario Galaxy.  While Super Mario Galaxy initially impresses more than Wario Land: Shake It!, after playing through it twice with Mario and Luigi I feel that I've seen all there is to see.  After playing Wario Land's levels several times, I know that there is plenty more to it. 

Anyone that says that the game is not long enough, has not tried to truely complete the game. 

I was about to post pretty much the same thing. I liked it, but it doesn't compare to the Wario Land games in my mind, and I wouldn't be surprised if many long time Wario fans feel the same.

Well everyone knew
De Blob>Wario Shake it!

That's why. Duh!

I loved the game. But as a side note, NSMBWii is so much better.

Loved the game but did not come back to get all the treasures in all levels. Mostly because I disliked the sub levels in the game (got all treasures and stars in all other 'normal stages' though). Then I didn't finish all the secret levels as I started playing something else at the time. Can' remember what though.

Wario was better. Much, much better.

Well, first of all, the game didn't do THAT bad in sales. No, it isn't selling 10 million like Mario Kart or New Super Mario Bros, but it still sold better than the avg third party title, at nearly 850,000 units.

There's a few reasons we can look at why the game didn't sell more. One, the series is traditionally a handheld series. And considering the fact that they opted to put a traditionally handheld series on a console could have hurt its sales. It seemed to be the case when the series went from handheld to console on the gamecube with Warioworld. Second of all, the game wasn't exactly deemed to be a 'hit'. Like I said before, its not something like Mario Galaxy or Smash Bros Brawl. It was just made to cater to those fans who already liked the series. And more than any game in the series, that's what it does.

Lastly, and this is going to be the hardest to hear, but despite the games excellent animations and attention to detail in the graphics department...it was a somewhat low budget title compared to other outings from Nintendo. In fact, you could even go so far as to say it feels like something the developers may have done as an 'in between' project. Now I'm not going to go as far as to say the game is bad...but it is rather repetitious and lacks much of the polish of other platformers from Nintendo in the gameplay department. Its also somewhat short for the main game, putting a lot of the gameplay into replaying all the levels for the 'extra' content. This may have deterred from its sales.