Keep your money
It's entirely possible that you will enjoy this game. The critics sure seemed to. But I didn't. I didn't absolutely hate it, and if nothing else, it definitely succeeded in being mysterious. But I certainly have no interest in playing it a second time.
There is such a thing as too minimalist and too abstract, and I think that's where Kairo has unfortunately landed itself. There's too much "nothing" to navigate to even get to the puzzles in the first place; the setting is far too open considering how little you get out of exploring it. The puzzles were very poorly designed, uninspired and lackluster. Unfortunately Kairo's setting worked *against* the the puzzles and good puzzle design in general, even though it needn't have. This was all the more disappointing to me considering how well-made Richard Perrin's debut game "the white chamber" was.
The hint system is also badly executed. The hints always seem to go from "not helpful" to "still not helpful" to "let's just basically tell you the answer and ruin it for you".
For those of you who have played Antichamber, allow me to draw a comparison: Antichamber succeeded where Kairo failed. Antichamber is inspired, inspiring, powerful, elegant, and unforgettable. Kairo, though it tried hard, is *none* of those things. If I try, I can recall moments that felt awe-inspiring at the time; but they have not stuck with me. They were forgettable, as was most of this game.