I hate these things so much that I ranked them as the fourth-worst obstacle when I wrote about them back in February 2016. They’re nothing like the easy blocks that you just have to destroy by matching next to them.
One-sided blocks have one light side and four dark sides, and the only way to match-and-destroy them is to match along the light side… which is almost always facing the wrong direction. Or, worse, two light sides are facing each other. There’s one level that I spent several dozen poops* trying to pass — it was all one-sided blocks with the light sides facing the wrong way, and only about 40 moves to do it in.
Destroy these annoyances as fast as possible, and don’t be shy about using your booster boxes if you have to. However, as with other blocks, they do keep fire and slime hemmed in (and water as well, so, not so good sometimes), so plan ahead.
If this guide helped you out, please consider buying one of my stories from Amazon. Here’s one: Amid the Steep Sky’s Commotion, as a reprint in Beyond Science Fiction. This one’s a steampunk murder mystery with a love story b-plot.