I love the presentation, but can't seem to understand the criteria of what constitutes a 3some. Going by the hints doesn't help, because it selects stuff that's not "everything matches or nothing does". Often it'll pick stuff with the same number, or two of the same number and shape, with one outlier, etc.
Honestly, it's not clear to me what the game accepts as a valid set, which gets quickly frustrating. There's a good solitaire matching game in there, but I think the explanation needs a lot of work, better examples, or something.