Patents give a temporary legal monopoly on an invention, but they don’t allow anticompetitive conduct outside the patent’s scope under the Sherman act and Clayton act if a patent is being used to restrain trade or build an unlawful monopoly/trust nintendos patent should therefore be unenforceable. And I don't think they actually could sue anyone and win. 

I may be wrong, but patent's give you a legal control about a specific implementation. Not a monololy over an invention (or an idea). For example, let's say you invent summoning mechanic for a game. This mechanic work by, idk, cloning a entity loeaded in memory. You can patent that exact way of doing so, not the summoning mechanic as a concept.

But if somebody else create a summonig mechanic that works creating the entity from scratch (not cloning anything from memory) so you can't sue this other dev, there is no patent violation. 

You patent the specific implementation of the idea, but not the idea itself. I think the Nintendo situation is because somebody in the patent's record office messed up things pretty bad. 

But i am agree, i think the pantent is unenforceable.