Well, hello, I managed to use lgogdownloader, which was a bit of a learning curve... now I downloaded the witcher 2 and while installing was a challenge in itself, launching the game, (even following the steps I've found in most forums here) is proving to be an almost impossible task. I'm using ubuntu 14.04 in an AMD 64x and a Geforece 750 ti with 12 RAM.... but I keep getting this, over and over again. Don't know what I'm looking at and not sure what I should keep or remove if something, please help me. T_T

It has a problem with Linux and I can't help you with that,aside from making sure Linux is set up properly.

Two dependancies are missing (not found).

Both libSDL2 and libSDL2_image will have to be installed according to your screenshot. Keep in mind that since Witcher 2 is 32-bit, you will have to install the 32-bit versions of the missing libraries.

Since I don't use Ubuntu myself I won't be able to tell you exactly where to get the libraries, but the following links might prove useful.

www.gog.com/forum/the_witcher_2/the_witcher_2_complains_cannot_open_libsdl220so0
packages.ubuntu.com/uk/trusty/all/libsdl2-image-2.0-0/filelist

Basically enabling multiarch (sudo dpkg --add-architecture i386 && sudo aptitude update) and installing the packages (sudo aptitude install libsdl2-2.0-0:i386 , sudo aptitude install libsdl2-image-2.0-0:i386) should fix your problem.

Hope this helps.