Played part 1 and 2 on my own and still had a good time.
There's some boring parts but the fun makes up for it.
And the humour. In part 1 there was a road warrior type enemy called Mad Mel
It's all time consuming but to me it's getting more for your money. I like games that take a while to complete. And most others are serious sci-fi or fantasy games. I want fun.