More than 20 hours' worth of game time ?!

[Stoker]

It took me 7 hours... Decent game though...

[bean]

20 houurs???

yea... no.

its a very short game.

[m.wing]

Hmm I would have said it was longer...

[bastikoester]

7 hours? seems very fast and not really believable. sorry

[bliss]

It took me 14 hours. I got stuck a couple of times.

[Adyman]

i like adventure games to play them slowly, this relax me! anyway this game is very good ;)

[Sweaty Betty]

Check this site out very useful.
http://www.howlongtobeat.com/game.php?id=134
10 hrs or so

[Lostedge]

Depends how many guides you check. Sure if you know what to do, it will take only like 3-4 hours.

[[x360] kazbeck1998]

Если не обращать внимания на достижения, то игру можно пройти 6-7 часов

[Faolchu]

I clocked 10 hours and a bit, skipped just one puzzle at the beginning because i didn't realise what the play button did. Quite an enjoyable adventure, most of the times very logical aswell. Recommended for persons who like adventures.

[Aron_dc]

I finished it in about 5-6 hours without any walkthrough and only skipped the binocular scene because I just couldn't figure out what i was supposed to do.

[Rzep]

Just finished and it took me around 7,5 hours. I wasnt rushing through it, and only skipped one of the puzzles in the end with the 3 chambers, was in a bad mood and didnt feel like thinking=) Overall nice game, I think the length was fine. The game didnt overstay its welcome, the puzzles didnt get in the way of the story. I hated the ending though, always hated all that semi dramatic sacrifice bull.

[Faolchu]

Took me around 10 hours, only auto resolved the first puzzle till i realised there are achievements for doing it right. Good game, very believable if you see the recent developments into Alge. They can make everything with it now and very cost effective. New strings are being discovered every day and the U.S. army is replacing it's fuel with Alge fuel. Promising future for a global replacement on fossil fuels.