A linux version for the game is available. Any way we can get this here on gog?

Maybe as extras, like the Interludes.

http://www.gog.com/wishlist/site/add_linux_versions_of_games
http://www.gog.com/forum/general/linux_support_on_gog/page1

Would be nice to get that ...
GoG has stated several times that currently they don't support Linux. Why? I don't know. Probably the old excuse about the claimed fragmentation of Linux. (a ridiculous argument)

Anyway: you could just buy the game on Humble Store, like I did. Same price as here, but you get the Linux version with it.

Mind you, in the readme.txt file of the Linux version Cardbord Computer (the maker of the game) states that the Linux version is to be considered as beta software. Ran fine on my machine, though.

@gog: sorry, for not buying it here, but I'm bored by your sorry excuses why not to support Linux. It's a non issue. Look: it works for Humble Bundle and quite a lot of game developers. Revolution supports it, even FEZ is available on Linux (even though the initial developer -- Phil Fish -- was banging on how this "is a console game for consoles". Admittedly: FEZ is not natively ported to Linux, but it still works well.) Curious, isn't it?!
And I just don't see the point in paying same price here as I'd do in Humble Store while getting less (i.e. no Linux version despite being readily available).
[edit: some corrections and a little addition]