Fun, wacky, cool, stupid, beautiful, and epic, Gitaroo Man is an experience that really everyone deserves to have. It's the only reason that I still own a PS2, as old and battered as it now is.
I played this with my brother, and then with my best friend at university, and we would keep going back time and again, trying to beat it on the very challenging Expert Mode. We'd break through it one stage at a time. Flying-O, Mojo King Bee, Ben-K, the Sanbone Trio, Gregorio, all seemingly insurmountable walls that we eventaully overcame one after the other.
It's a short game if you can beat it start to finish, but the songs, the visuals and the difficulty level of Expert Mode kept the three of us coming back again and again. I think it's such a shame that this game is as niche as it is, and I'd love more people to have this fantastic experience.