While Cinco Paus is the objectively correct vote, I’ll add a couple of nominations that I haven’t seen mentioned yet and I believe deserve to have at least a ballot slot. The Room: Old Sins, and Six Ages: Ride Like the Wind.
(I’d have added Slay the Spire, but that apparently fails to make the cut-off, having been released in Early Access on 15th November last year, though SP didn’t discover it until January.)