Plinko is not one game but a format, implemented by several studios. The differences are in payout tables, row options and presentation rather than in the underlying idea.
What differs between versions
Row options. Some offer eight to sixteen, others a fixed count.
Risk settings. Usually three levels; the exact multipliers differ.
Published RTP. The spread across studios runs from about 97% to 99%, which is a
meaningful difference over many rounds.
Fairness data. Some publish seed pairs for
verification; others rely on licence and testing certificates
instead.
What does not differ
The distribution. Every implementation puts the common outcomes in the centre and the rare
ones at the edges, because that follows from the shape of the board rather than from any
design decision. The probabilities are the same everywhere for a given
row count.
Choosing between them
Compare published RTP first, then whether fairness data is available, then whether the row
and risk options suit how you want to play. Presentation is the least important difference and
the most heavily marketed one.