I've been reading more on this, and even the 20 hours doesn't include the secret Galaxies that you'll unlock through exploration. These aren't required to beat the game but they are levels that you get only by exploring.

Legend, neogaf users are hardly a credible source.  The first one directly contradicted every single review source who has claimed the game is incredibly hard.  The 1UP reviewer claimed he died 15 times in under 3 minutes in one level.  The second guy, who sounded like he actually beat the game, noted that he had only beaten the main levels.  Surely you consider hidden Galaxies a more tangible way to increase play time than Achievement points.... 

Hahaha...

Stars, and achievements, are two totally different things. Achievements in 360 games are just little goals you can set for yourself within the main.

Getting stars is actual completely new content, with different level layouts and objectives.

That said, I've hear 20+ hours from most sources.

Is the big news that SMG is speed-runnable?

What's the record for Super Mario 3? Five minutes?

The problem is that Mario Galaxy, unlike those games, is not a short game. Once again, all reviewers are reporting 20+ hours just for finishing the game, WITHOUT (read this part) all the stars.

If you want all the stars is 30+ hours.

This is obviously without counting walkthroughs and speed runs, otherwise all games would be below 2 hours

Okay, the 7 hours you noted says play thorugh carefully, but then clearly states that playing through it only to get the "required star" to get through that galaxy (speed run). The 14~15 hour game is for 85 stars, and it's still in Mario mode. Both of these posts praised the game immensely...

I am not really sure what you are trying to get since the 1st person took the easiest route to play, which is also how people usually play speed runs. The 2nd one have gotten the 85 stars that's easiest to get before the last 35 stars from comet run, but have yet to go into "hard" mode. I would think that you would only count total time if said person actually "finish" the game?

P.S. People who have read the spoiler thread will know what I am talking about by "hard" mode

When (pretty much) every reviewer mentions that a game is less than 8 hours it stops being trolling in a discussion and becomes a fact

http://www.neogaf.com/forum/showpost.php?p=8463289&postcount=5880 (7 hours)

"Overall the game took me 7 hours to beat, taking my time to finish each galaxy until I reached the required number of stars to go to the end."

Just the minimum to finish the game... somehow reminds me the speed runners....

http://www.neogaf.com/forum/showpost.php?p=8475999&postcount=6035  (~14-15 hours)

"Alright, finished the game. Total time was ~14-15 hours. "
 

"So they sucked all that out and just left room after room of pure gameplay for 15-20 hours with no bullshit"

So, is 14, or 15-20 hours long???

Edit: Links added... 

Sorry but I'm tired of Mario regardless of how long and how good the game may be. I'm getting Z&W.
Can't wait till Mass Effect - the (maybe) GOTY.

Bah FJ Warez I was going to post exactly what you just did, but VGchartz died while it was posting =(

Here's another quote about length from there: "It probably took me about 12-15 hours to get 61 stars and beat the game, but I imagine my total will be somewhere around 60-80 once I get all 120 stars."

http://www.neogaf.com/forum/showpost.php?p=8478502&postcount=6064

This is the best thing I've heard about the game so far:

"The game is really fantastic all around. What's nice is that Nintendo basically looked at Sunshine, looked at TP, looked at WW, and realized what brings the games down is the filler/tedious sections. So they sucked all that out and just left room after room of pure gameplay for 15-20 hours with no bullshit, and I approve highly of that"

And that was from the 14-15 hours guy.

yes, that's the mode I meant, but I am trying not to spoil it in case someone have not heard of it. There's also some other rumor about another unlocakable getting all 120 stars in hard mode, though I have not seen a single proof for it, and only proof contradicting it.