I really don't know whether to even bother reviewing this episode! I suppose I'd better. All I really have to say about this episode is that it was crap. I laughed once, at the Scrabble-Ships game at the beginning, but after this I couldn't laugh at anything.
It's a shame, really, because Grampa is a funny character, but only when he's being senile or old-fashioned. He is just not funny when trying to be young and hip.
I also noticed Homer was shouting a lot in this episode - it's pretty much all he did. The plot was a bit stupid, too. I think that's all I am going to write.