I only went through a first (which I survived), but I was actually more interested in observing my thought processes. I pretty much had to go by general sound, as I mostly got languages I know little about.
Some of the ones I got right:
Doesn't sound tonal. Can't be Mandarin.
Full of gutturals. Must be Hebrew.
I recognize a couple of words--Dutch!
Vaguely reminds me of Turkish. Must be Finnish.
I've heard enough spoken Vietnamese that it just doesn't sound right. Must be Lao.
Naturally I got tripped up when the choices were Danish, Norwegian, and Swahili. Obviously a Scandinavian language, but that was my only clue, since I know nothing about any of them. Flipped a coin & got it wrong.
Also got it wrong when the choices were Hindi and two languages I'd never heard of. It was Hindi.