Well, *generally* when a game gets released on several platforms at once, you're getting the same game. When it comes to console vs. handheld vs. mobile, it varies a bit, for sure. Not usually as much as that Grandia II mess, of course, though I know the first time I played a Telltale game on my old iPad, the performance was subpar vs other platforms. (or my newer iPad)
The possible distinctions are why, under platforms on reviews, we added a "reviewed on" field, so at least you know what version we played. We feel it's still worth listing on each platform page, though, simply because the core game is going to be the same, and in most cases (say, PS3/360 releases, and usually PS4/XB1), performance will also be largely the same.
That said, were it feasible for us to review every possibly different release - at least to have general 'console,' 'PC,' and 'mobile' reviews - we likely would, but there's only so much time in the day, haha. So in the end, if we can't do that, we think it's best doing what we do, since we wouldn't want someone to visit one platform's page and assume we don't have a review at all for a game. Or force them to peck around each platform to check.
So that's my long-winded explanation. Hope that makes sense! We don't really explain this policy anywhere on the site, so this was a good question to bring up. Do let us know if you have any others. ^^