I'm currently playing through it with a gamer buddy. The gameplay isn't challenging, but it's definitely fun. I was talking to someone else who tried playing with their non-gamer wife, but they had to stop because she was getting frustrated with things.
I agree about the writing and it being the weakest point. Then there's the part with the elephant:
spoiler
What the fuck, that was really dark and gruesome. These parents are pretty shitty people.
The level design and environments are excellent, though. Between these and the gameplay, the game is still a joy to play through, even if the writing sours the experience a bit. Split Fiction is definitely on my watchlist, and I plan on picking it up during a sale.